Q8 of 90 Page 111

Two numbers are such that the ratio between them is 3 : 5. If each is increased by 10, the ratio between the new numbers so formed is 5:7. Find the original numbers.

Let the numbers be 3x and 5x


According to the question



By cross multiplication


⇒ 7(3x + 10) = 5(5x + 10)


⇒ 21x + 70 = 25x + 50


⇒ 4x = 20


⇒ x = 5


So the numbers are 3x = 3 × 5 = 15 and 5x = 5 × 5 = 25


More from this chapter

All 90 →
6

Three numbers are in the ratio of 4 : 5 : 6. If the sum of the largest and the smallest equals the sum of the third and 55, find the numbers.

 7

If 10 be added to four times a certain number, the result is 5 less than five times the number. Find the number.

 9

Find three consecutive odd numbers whose sum is 147. Hint. Let the required numbers be (2x + 1), (2x + 3) and (2x + 5).

 10

Find three consecutive even numbers whose sum is 234.

Hint. Let the required numbers be 2x, (2x + 2) and (2x + 4).