Question

A positive number is 5 times another number. If 21 is added to both the numbers,

then one of the new numbers becomes twice the other new number. What are the
numbers?

Answer 1

7 and 35

Explanation:

let the numbers be n and 5n , then when 21 is added to both they are

n + 21 and 5n + 21

Given that one is twice the other

5n + 21 = 2(n + 21)

5n + 21 = 2n + 42 ( subtract 2n from both sides )

3n + 21 = 42 ( subtract 21 from both sides )

3n = 21 ( divide both sides by 3 )

n = 7

and 5n = 5 × 7 = 35

The numbers are 7 and 35