Question

If you take a number and add a zero to the right and subtract the result from 143, you'll get three times the original number. what is the number

Answer 1

Let the number be n.
Adding a zero means multiplying the number by 10, 10n.
143-10n=3n, 13n=143 so n=11.

Answer 2

11

Explanation:

Let the number be x. If zero is added to the right of the number, this is equivalent to multiplying the number by 10

Hence x0 = 10x

143 - 10x = 3x

collect like terms

3x + 10x = 143

13x = 143

x = 143/13

x = 13

The number is 11.