GRADE 7 MATH WORKSHEET 15 ANSWERS

About "Grade 7 math worksheet 15 answers"  

Grade 7 math worksheet 15 answers :

Here we are going to see 10 practice questions of mixed topics. We have been preparing this set of questions in order to test how you understood the topics.

Practice questions of mixed topics in 7th grade math

Question 1 :

In a school the total enrollment of class 8th is 115. If the number of boys exceeds the number of girls by 33, find the number of boys in a class 8th.

(A) 74            (B) 89            (C) 50

Solution :

Let "x" be the number of girls

Number of boys  =  x + 33

Total number of students in the class  =  115

x + x + 33  =  115

2x + 33  =  115

Subtract 33 on both sides

2x  =  115 - 33

2x  =  82

Divide by 2 on both sides

x  =  41

x + 33  =  74

Hence the number of boys in the class is 74.

Question 2 :

One of the angles of a triangles is equal to the sum of the remaining tow angles. If the ratio of these angles is 4:5, find the angles of the given triangle.

(A) 60, 60, 60        (B) 60, 80, 40          (C) 40, 50, 90

Solution :

Let the three angles be "9x", "4x" and "5x"

Sum of three angles  =  180°

4x + 5x + 4x + 5x  =  180°

8x + 10x  =  180°

18x  =  180°  ==>  x  =  18°

Hence the angles are 90, 50, 40.  

Question 3 :

Two equal sides of a triangle are each 4 m less than three times the third side.Find the dimensions of a triangle,if its perimeter is 55 m.

(A) 15, 15, 8              (B) 23, 23, 9         (C) 13, 13, 8

Solution :

Let "x" be the third side of the triangle

Length of two equal sides  =  3x - 4

Perimeter of triangle  =  55 m

3x - 4 + 3x - 4 + x  =  55

7x - 8  =  55

Add both sides by 8

7x  =  63

Divide both sides by 7

x  =  9

3x - 4  =  3(9) - 4  ==> 27 - 4  ==> 23

Hence the required angles are 23, 23, and 9

Question 4 :

If a + 1/a = 2, find the value of a3 + (1/a)3

(A) 1            (B) 2             (C) 3

Solution :

To find the value of a3 + (1/a)3, we may use the formula given below.

(a + b)3  =  a3 + b3 + 3ab(a + b)

a3 + a1/3  =  (a + (1/a))+ 3 a (1/a)(a + (1/a))

=  23 + 3 (2)

=  8 + 6

  =  14

Hence the answer is 14.

Let us look into the solution of next problem on "Grade 7 math worksheet 15 answers".

Question 5 :

A gardener bought twice the number of Lilly plants that he had in his garden but had to throw 3 bad plants. When the new Lilly plants were planted, he had in all 48 plants in the garden.Find the number of Lilly plants he had originally.

(A) 17                 (B) 15               (C) 13

Solution :

Let "x" be the number of lilly plants in his garden

Number of plants he buys  =  2x

2x + x - 3  = 48

3x - 3  =  48

Add both sides by 3

3x  =  48 + 3

3x  =  51

Divide both sides by 3

x  =  51/3  =  17

Hence the number of Lilly plants in the garden is 17.

Let us look into the solution of next problem on "Grade 7 math worksheet 15 answers".

Question 6 :

Simplify a3 - b3 ÷ (a-b)

(A) a+ ab + b2          (B) a- ab + b2         (C) (a+b) (a+b)

Solution :

a3 - b=  (a - b) (a+ ab + b2)

a3 - b3 ÷ (a - b)  =  (a - b) (a+ ab + b2) / (a - b)

=  a+ ab + b2

Let us look into the solution of next problem on "Grade 7 math worksheet 15 answers".

Question 7 :

If a + b + c = 9 and ab + bc + ca = 23, find the value of a2 + b2 + c2

(A) 15            (B) 12               (C) 35

Solution :

(a + b + c)2  =  a2 + b2 + c+ 2ab + 2bc + 2ca

(a + b + c)2  =  a2 + b2 + c2  + 2(ab + bc + ca)

 a2 + b2 + c2 = (a + b + c)2 - 2(ab + bc + ca)

= (9)2 - 2 (23)

=  81 - 46  =  35

Hence the answer is 35.

Let us look into the solution of next problem on "Grade 7 math worksheet 15 answers".

Question 8 :

The difference between the compound interest and the simple interest on a certain principal for 2 years at 4% per annum is $150. Find the principal

(A) 1875           (B) 3750           (C) 1263

Solution :

Simple interest  =  PNR/100

150  =  P(2)(4) / 100

150  =  8 P / 100

Multiply both sides by 100

150 (100)  =  8 P

Divide both sides by 8

P  =  150(100) / 8

=  1875

Hence the principal amount is 1875.

Let us look into the solution of next problem on "Grade 7 math worksheet 15 answers".

Question 9 :

The watch is marked at $1150. During off season a discount given and it is sold for $1100. Find the discount percent allowed.

(A) 2.14%          (B) 4.34%            (C) 3.04%

Solution :

Discount percentage

  =  (Discount amount / Marked price) ⋅ 100

Discount amount  =  1150  -  1100  =  50

  =  (50/1150) ⋅ 100

=  0.0434 (100)

=  4.34%

Let us look into the solution of next problem on "Grade 7 math worksheet 15 answers".

Question 10 :

What must be added to each of the numerator and the denominator of the fraction 7/11 to make it equal to 3/4 

(A) 2             (B) 8             (C) 5

Solution :

Let "x" be the required number to be added to both numerator and denominator.

(7 + x) / (11 + x)  =  3/4

4 (7 + x)  =  3 (11 + x)

28 + 4x  =  33 + 3x 

4x - 3x  =  33 - 28

x  =  5

After having gone through the stuff given above, we hope that the students would have understood "7th grade math worksheet 15 answers". 

Apart from the stuff given above, if you want to know more about "7th grade math worksheet 15 answers" Apart from the stuff, if you need any other stuff in math, please use our google custom search here. 

HTML Comment Box is loading comments...

ALGEBRA

Variables and constants

Writing and evaluating expressions

Solving linear equations using elimination method

Solving linear equations using substitution method

Solving linear equations using cross multiplication method

Solving one step equations

Solving quadratic equations by factoring

Solving quadratic equations by quadratic formula

Solving quadratic equations by completing square

Nature of the roots of a quadratic equations

Sum and product of the roots of a quadratic equations 

Algebraic identities

Solving absolute value equations 

Solving Absolute value inequalities

Graphing absolute value equations  

Combining like terms

Square root of polynomials 

HCF and LCM 

Remainder theorem

Synthetic division

Logarithmic problems

Simplifying radical expression

Comparing surds

Simplifying logarithmic expressions

Negative exponents rules

Scientific notations

Exponents and power

COMPETITIVE EXAMS

Quantitative aptitude

Multiplication tricks

APTITUDE TESTS ONLINE

Aptitude test online

ACT MATH ONLINE TEST

Test - I

Test - II

TRANSFORMATIONS OF FUNCTIONS

Horizontal translation

Vertical translation

Reflection through x -axis

Reflection through y -axis

Horizontal expansion and compression

Vertical  expansion and compression

Rotation transformation

Geometry transformation

Translation transformation

Dilation transformation matrix

Transformations using matrices

ORDER OF OPERATIONS

BODMAS Rule

PEMDAS Rule

WORKSHEETS

Converting customary units worksheet

Converting metric units worksheet

Decimal representation worksheets

Double facts worksheets

Missing addend worksheets

Mensuration worksheets

Geometry worksheets

Comparing  rates worksheet

Customary units worksheet

Metric units worksheet

Complementary and supplementary worksheet

Complementary and supplementary word problems worksheet

Area and perimeter worksheets

Sum of the angles in a triangle is 180 degree worksheet

Types of angles worksheet

Properties of parallelogram worksheet

Proving triangle congruence worksheet

Special line segments in triangles worksheet

Proving trigonometric identities worksheet

Properties of triangle worksheet

Estimating percent worksheets

Quadratic equations word problems worksheet

Integers and absolute value worksheets

Decimal place value worksheets

Distributive property of multiplication worksheet - I

Distributive property of multiplication worksheet - II

Writing and evaluating expressions worksheet

Nature of the roots of a quadratic equation worksheets

Determine if the relationship is proportional worksheet

TRIGONOMETRY

SOHCAHTOA

Trigonometric ratio table

Problems on trigonometric ratios

Trigonometric ratios of some specific angles

ASTC formula

All silver tea cups

All students take calculus 

All sin tan cos rule

Trigonometric ratios of some negative angles

Trigonometric ratios of 90 degree minus theta

Trigonometric ratios of 90 degree plus theta

Trigonometric ratios of 180 degree plus theta

Trigonometric ratios of 180 degree minus theta

Trigonometric ratios of 180 degree plus theta

Trigonometric ratios of 270 degree minus theta

Trigonometric ratios of 270 degree plus theta

Trigonometric ratios of angles greater than or equal to 360 degree

Trigonometric ratios of complementary angles

Trigonometric ratios of supplementary angles 

Trigonometric identities 

Problems on trigonometric identities 

Trigonometry heights and distances

Domain and range of trigonometric functions 

Domain and range of inverse  trigonometric functions

Solving word problems in trigonometry

Pythagorean theorem

MENSURATION

Mensuration formulas

Area and perimeter

Volume

GEOMETRY

Types of angles 

Types of triangles

Properties of triangle

Sum of the angle in a triangle is 180 degree

Properties of parallelogram

Construction of triangles - I 

Construction of triangles - II

Construction of triangles - III

Construction of angles - I 

Construction of angles - II

Construction angle bisector

Construction of perpendicular

Construction of perpendicular bisector

Geometry dictionary

Geometry questions 

Angle bisector theorem

Basic proportionality theorem

ANALYTICAL GEOMETRY

Analytical geometry formulas

Distance between two points

Different forms equations of straight lines

Point of intersection

Slope of the line 

Perpendicular distance

Midpoint

Area of triangle

Area of quadrilateral

Parabola

CALCULATORS

Matrix Calculators

Analytical geometry calculators

Statistics calculators

Mensuration calculators

Algebra calculators

Chemistry periodic calculator

MATH FOR KIDS

Missing addend 

Double facts 

Doubles word problems

LIFE MATHEMATICS

Direct proportion and inverse proportion

Constant of proportionality 

Unitary method direct variation

Unitary method inverse variation

Unitary method time and work

SYMMETRY

Order of rotational symmetry

Order of rotational symmetry of a circle

Order of rotational symmetry of a square

Lines of symmetry

CONVERSIONS

Converting metric units

Converting customary units

WORD PROBLEMS

HCF and LCM  word problems

Word problems on simple equations 

Word problems on linear equations 

Word problems on quadratic equations

Algebra word problems

Word problems on trains

Area and perimeter word problems

Word problems on direct variation and inverse variation 

Word problems on unit price

Word problems on unit rate 

Word problems on comparing rates

Converting customary units word problems 

Converting metric units word problems

Word problems on simple interest

Word problems on compound interest

Word problems on types of angles 

Complementary and supplementary angles word problems

Double facts word problems

Trigonometry word problems

Percentage word problems 

Profit and loss word problems 

Markup and markdown word problems 

Decimal word problems

Word problems on fractions

Word problems on mixed fractrions

One step equation word problems

Linear inequalities word problems

Ratio and proportion word problems

Time and work word problems

Word problems on sets and venn diagrams

Word problems on ages

Pythagorean theorem word problems

Percent of a number word problems

Word problems on constant speed

Word problems on average speed 

Word problems on sum of the angles of a triangle is 180 degree

OTHER TOPICS 

Profit and loss shortcuts

Percentage shortcuts

Times table shortcuts

Time, speed and distance shortcuts

Ratio and proportion shortcuts

Domain and range of rational functions

Domain and range of rational functions with holes

Graphing rational functions

Graphing rational functions with holes

Converting repeating decimals in to fractions

Decimal representation of rational numbers

Finding square root using long division

L.C.M method to solve time and work problems

Translating the word problems in to algebraic expressions

Remainder when 2 power 256 is divided by 17

Remainder when 17 power 23 is divided by 16

Sum of all three digit numbers divisible by 6

Sum of all three digit numbers divisible by 7

Sum of all three digit numbers divisible by 8

Sum of all three digit numbers formed using 1, 3, 4

Sum of all three four digit numbers formed with non zero digits

Sum of all three four digit numbers formed using 0, 1, 2, 3

Sum of all three four digit numbers formed using 1, 2, 5, 6