Three women, Mary, Pamela and Usha went on a shopping spree. 70% of Mary's spending was equal to ¹₆ of Pamela's spending. Usha's spending was  50% more than Pamela's. If Pamela spent another $1617, she would spend the same amount of money as Usha.

1. Find the ratio of Mary's spending to Pamela's to Usha's.
2. How much did Mary spend?

Mary	Pamela	Usha
5x2	21x2
	2x21	3x21
10 u	42 u	63 u

(a)
70%= ⁷⁰₁₀₀ = ⁷₁₀
⁷₁₀ of Mary's spending is equal to ¹₆ of Pamela's spending. Make the numerators the same.  LCM of 7 and 1 is 7.

710 of Mary's spending = 16 of Pamela's spending
710 of Mary's spending =1x76x7 of Pamela's spending
710 of Mary's spending = 742 of Pamela's spending

Mary : Pamela
10 : 42
5 : 21

Usha's spending in percent when compared to Pamela's
= 100% + 50%
= 150%

Pamela : Usha
100 : 150
2 : 3

Pamela's spending is the repeated identity.  Make Pamela's spending the same.  LCM of 21 and 2 is 42.

Mary : Pamela : Usha
10 : 42 : 63

(b)

	Mary	Pamela	Usha
Before	10 u	42 u	63 u
Change		+ 21 u
After	10 u	63 u	63 u

Additional amount that Pamela would have to spend to be the same as Usha
= 63 u - 42 u
= 21 u

21 u = 1617

1 u = 1617 ÷ 21 = 77

Amount that Mary spent
= 10 u
= 10 x 77
= $770 

Answer(s): (a) 10 : 42 : 63; (b) $770