Question

Two numbers are in the ratio of 3 : 4. If 4 be added to each, the ratio becomes 4 : 5, find the numbers.

Answer 1

Let the two numbers be 3x and 4x.

After adding 4 to each, the ratio becomes:

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

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

15x + 20 = 16x + 16

15x − 16x = 16 − 20

−x = −4

x = 4

Find the numbers:

First number = 3x = 3 × 4 = 12

Second number = 4x = 4 × 4 = 16

∴ The two original numbers are 12 and 16.