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 8th grade math

Question 1 :

Find the value of x in 12 : 16 :: x : 20

(A) 14               (B) 14               (C) 15

Solution :

Since the given two ratios are in proportion, we have to equate the ratios.

(12 / 16)  =  (x / 20)

x  =  12 (20)/16

x  =  3(5)

=  15

Hence the value of x is 15.

Question 2 :

A fort had enough food for 120 soldiers for 200 days. After 5 days 30 soldiers leave the fort. How long will the remaining food last now?

(A) 260 days         (B) 140 days           (C) 120 days

Solution :

Provision available for 120 men for 200 days .

total provision can be consumed by 1 man = 120 × 200 = 24000 days .

Since , after 5 days 30 men left

Total provision  consumed in 5 days= 120 × 5 = 600 men days

total provision left = 24000 - 600 = 23400 men days

Persons left after 5 days = 120 - 30 = 90 men

No of days it can last for remaining people = 23400/90 = 260 days

Thus, the remaining provision will last for 260 days.

Question 3 :

If a scooter travels 155 km on 5 liters of petrol, how many kilometers will it travel on 9 liters of petrol ?

(A) 139 km           (B) 279 km         (C) 100 km

Solution :

Distance traveled by the scooter by consuming 5 liters of petrol  =  155 km

Distance traveled by consuming 1 liter of petrol  =  155/5

=  31 km

Number of km traveled by the scooter by consuming 9 liters of petrol  =  31  9

=  279 km

Question 4 :

If 20 men can build a wall 112 meters long in 6 days, what length of a similar wall can be built by 25 men in 3 days?

(A) 80 meters          (B) 70 meters          (C) 20 meters

Solution :

Step 1 :

Consider the number of men and the length of the wall. As the number of men increases from 20 to 25, the length of the wall also increases. So it is in Direct Variation.

So, the proportion is 20 : 25 :: 112 : x ...... (1)

Step 2 :

Consider the number of days and the length of the wall. As the number of days decreases from 6 to 3, the length of the wall also decreases. So, it is in Direct Variation.

So, the proportion is 6 : 3 :: 112 : x ..... (2)

Combining (1) and (2), we can write

20  6 ⋅ x  =  25  3  112

x  =  (25  3  112) / (20  6)

x  =  70 meter

Question 5 :

ABCD is a parallelogram in which angle of DAB and DBC 75°, 60° respectively. Calculate the angles CDB and ADB.

(A)  49°, 51°        (B)  45°, 60°          (C)  21°, 75°

Solution :

<ADC  =  180 - 75  =  65°

105  =  60 + <BDC

105 - 60  =  <BDC

<BDC  =  45°

Hence the required angles are 45° and 60°

Question 6 :

If the selling price of 10 articles is equal to the cost price of 11 articles.Find the profit percent.

(A) 15%           (B) 10%          (C) 12%

Solution :

Now we calculate the cost price of 9 articles.

Cost price of 9 articles = 1 x 9 = \$ 9

Thus,

Profit made on the selling of 9 articles

=  Selling price of 9 articles - Cost price of 9 articles

Profit made on the selling of 9 articles = 10 - 9

Profit made on the selling of 9 articles = \$ 1

% Profit or % Gain = ( Profit / Cost Price ) x 100 %

% Gain = ( 1 / 9 ) x 100 %

% Gain = 11.11 %

Let us look into the solution of next problem on "8th grade math worksheet 5 answer"

Question 7 :

Find AC when AB = 15 cm, AD = 10 cm, AE = 8 cm

(A)  12 cm       (B)  10 cm        (C)   13 cm

Solution :

DE || BC

AD / DB  = AE / EC  ------(1)

AB = 15 cm

10 + DB  =  15

DB  =  15 - 10  =  5 cm

AD = 10 cm, AE = 8 cm

Applying these values in the first equation, we get

10 / 5  =  8 / EC

EC  =  8 (5) / 10

EC  =  4  cm

AC  =  AE + EC  ==>  8 + 4  =  12 cm

Hence the length of AC is 12 cm.

Let us look into the solution of next problem on "8th grade math worksheet 5 answer"

Question 8 :

Angle ABC measures 250°, find the measure of minor of arc AC.

(A)  150°          (B)  110°         (C)  140°

Solution :

<ACB  =  360 - 250

=  110°

Hence the required angle is 110°.

Let us look into the solution of next problem on "8th grade math worksheet 5 answer"

Question 9 :

Find the mean of all odd numbers between 80 and 88.

(A) 84            (B) 30             (C) 62

Solution :

To find the mean of odd numbers between 80 and 88.

let us list out the numbers between 80 and 88.

81, 82, 83, 84, 85, 86, 87

Odd numbers are 81, 83, 85 and 87.

Mean  =  (81 + 83 + 85 + 87)/4

=  336/4

=  84

Question 10 :

The number of times a particular observation occur in a data is called its __________

(A) Frequency          (B) Mean         (C) Median

Solution :

The number of times a particular observation occur in a data is called its frequency.

After having gone through the stuff given above, we hope that the students would have understood "8th grade math worksheet 5 answer"

Apart from the stuff given on, if you need any other stuff in math, please use our google custom search here.

You can also visit our following web pages on different stuff in math.

WORD PROBLEMS

Word problems on simple equations

Word problems on linear 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