Question

. Jane can paint the office by herself in 7 hours. Working with an associate, she can paint the

office in 3 hours. How long would it take her associate to do it working alone?
Let x be Jane, and y be her associate.

Answer 1

Explanation:

She can paint 7/7 in 7 hours so that she can paint 1/7 in 1 hour

With an associate, they can paint 3/3 in 3 hours so that they can paint 1/3 in 1 hour

The difference in 1 hour (ie the amount the associate can paint on their own) is

1/3 - 1/7 = 7/21 - 3/21 = 4/21

To paint 21/21 it would be the number of times 421 would fit into 21/21 ie

21/4 hours = = 5 1/4 hours