Solution of Question1and2

In this page solution of question1and2 we are going to see solution of first,second and third question.

Question 1:

The sum of two numbers is 90  and they are in the  ratio is 4:5. Find those numbers.

Solution:

Let "x" be first number

So "90-x" will be the second number (Because sum of those two numbers is 90)

Those numbers are in the ratio 4:5. So x : (90- x) = 4 : 5

                              x/(90-x) =  4/5

                                     5 x =  4(90 - x)

                                     5 x = 360 - 4 x 

                             5 x + 4 x = 360

                                     9 x = 360

                                       x = 360/9

                                       x = 40

So the first number  x = 40

and the second number 90 - x = 90 - 40 = 50

Therefore the correct option is (B) 40 and 50

Question 2:

If the same numbers is added to both the numerator and denominator of a fraction 3/5, then the result is 3/4. Find the number.

Solution:

Let "x" be the required number.

If it is added with numerator and denominator of the fraction 3/5. It will become (3 + x)/ (5 + x).

                 (3 + x)/ (5 + x) = 3/4

                          4 (3 + x) = 3 (5 + x)

                          12 + 4 x = 15 + 3 x

                          4 x - 3 x = 15 - 12

                                    x = 3

Therefore the correct option is (A) 3


Question 3:

Two numbers are such that the ratio between them is 5 : 7. When 7 is added to each of them, the ratio becomes 2 : 3. Find the numbers.

Solution:

Let "5 x" and "7 x" be two numbers.

When two numbers is added by 7 we will get 5 x + 7 and 7 x + 7.

                    (5 x + 7) : (7 x + 7) = 2 : 3

                      (5 x + 7)/(7 x + 7) = 2/3

                                3 (5 x + 7) = 2 (7 x + 7)

                                  15 x + 21 = 14 x  + 14

                                15 x - 14 x = 14 - 21

                                             x = -7

 The value of 5x = 5 (-7) = - 35

 The value of 7x = 7(-7) = - 49

So the two numbers are -35 and -49.

Therefore the correct option is (C) -35 and -49



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