Bryan, Adam and Charlie have $1422.
After Bryan spends ²₃ of his money,
Adam spends ⁴₇ of his money and
Charlie spends ¹₅ of his money,
they have equal amount of money left.
Find the total amount that the 3 children spend.

	Bryan	Adam	Charlie
Before	3 x 12 = 36 u	7 x 4 = 28 u	5 x 3 = 15 u
Change	- 2 x 12 = - 24 u	- 4 x 4 = - 16 u	- 1 x 3 = - 3 u
After	1 x 12 =  12 u	3 x 4 = 12 u	4 x 3 = 12 u

The lowest common multiple of 1, 3 and 4 is 12.

Fraction of the amount left after Bryan spends his money
= 1 - ²₃
= ¹₃

Fraction of the amount left after Adam spends his money
= 1 - ⁴₇
= ³₇

Fraction of the amount left after Charlie spends his money
= 1 - ¹₅
= ⁴₅

Make the numerators the same.
1 x 123 x 12 of Bryan's amount = 3 x 47 x 4 of Adam's amount = 4 x 35 x 3 of Charlie's amount
1236 of Bryan's amount = 1228 of Adam's amount = 1215 of Charlie's amount

Total amount that they have at first
= 36 u + 28 u + 15 u
= 79 u

79 u = 1422

1 u = 1422 ÷ 79 = 18

Amount that Bryan spends
= 36 u - 12 u
= 24 u

Amount that Adam spends
= 28 u - 12 u
= 16 u

Amount that Charlie spends
= 15 u - 12 u
= 3 u

Amount that they spend
= 24 u + 16 u + 3 u
= 43 u
= 43 x 18
= $774

Answer(s): $774