Michael's and Cindy's monthly allowances were the same at first. Michael's allowance increased by 50% while Cindy's increased by 25%. Given that Michael's allowance would increase by another 30% if he had received $621 more from his parent, find the difference in the children's monthly allowances.

	Michael	Cindy
Before	1 u	1 u
Change 1	+ 0.5 u	+ 0.25 u
After 1	1.5 u	1.25 u
Change 2	+ 0.45 u	No change
After 2	1.95 u	1.25 u

Increase in Michael's allowance
= 50% x 1 u
= ⁵⁰₁₀₀ x 1 u
= 0.5 u

Increase in Cindy's allowance
= 25% x 1 u
= ²⁵₁₀₀ x 1 u
= 0.25 u

Increase in Michael's allowance if his parent gave another $621
= 30% x 1.5 u
= ³⁰₁₀₀ x 1.5 u
= 0.45 u

0.45 u = 621

1 u = 621 ÷ 0.45 = 1380

Difference in the allowance between Michael and Cindy
= 1.5 u - 1.25 u
= 0.25 u
= 0.25 x 1380
= $345

Answer(s): $345