Dean and Patrick brought some money for shopping. The ratio of the amount of money Dean had to the amount of amount Patrick had was 3:8. The ratio of the amount of money Dean spent to the amount of money Patrick spent was 3:5. Dean spent 3/4 of his money and Patrick had $136 left. What was the total amount of money they brought for shopping?
D==Dean's money, P==Patrick's money
d==How much Dean spent, p==How much Patrick spent
D/P == 3/8..................... (1)
d/p==3/5........................ (2)
D - d ==1/4D.................. (3)
P - p==136..................... (4), solve for D, P, d, p
From (1) and (2) above, we have:
d==0.60p and D==0.375P (5)
Sub d and D in (3) above and we have:
0.375P - 0.60p ==1/4 * 0.375P
P - p == 136, solve for P, p
P==$256 - Patrick's money
p==$120 - what Patrick spent
Sub P and p into (5) above:
D==0.375 * 256==$96 Deans money
d==0.60 * 120==$72 - what Dean spent.