70% of Cathy's amount was $126 more than Ian's amount. When Cathy spent 60% of her amount and Ian spent 30% of his amount, they had the same amount of amount left. Find the amount that Ian had at first.

	70% of Cathy's amount	Cathy's amount	Ian's amount
Before	24.5 u	35 u	20 u
Change		- 21 u (- 60%)	- 6 u (- 30%)
After		14 u	14 u

Percentage of Cathy's amount left
= 100% - 60%
= 40%

Percentage of Ian's amount left
= 100% - 30%
= 70%

40% = ⁴⁰₁₀₀ = ²₅
70% = ⁷⁰₁₀₀ = ⁷₁₀

The amounts of amount that Cathy and Ian had left were the same.
Make the numerators the same.

²₅ of Cathy's amount = ⁷₁₀ of Ian's amount
¹⁴₃₅ of Cathy's amount = ¹⁴₂₀ of Ian's amount

Amount that Cathy had = 35 u

70% of the amount that Cathy had
= 35 u x 70%
= 35 u x ⁷⁰₁₀₀
= 24.5 u

Difference between 70% of Cathy's amount and Ian's amount
= 24.5 u - 20 u 
= 4.5 u

4.5 u = 126
1 u = 126 ÷ 4.5 = 28

Amount that Ian had at first
= 20 u
= 20 x 28
= $560

Answer(s): $560