Sam has some quarters, nickels, and dimes. He has 4 more quarters than dimes and 3 more dimes than nickels. If n represents the number of nickels he has, which of the following represents, in cents, the total value of all his coins?
A) 40n+205
B) 40n+130
C) 40n+ 7
D) 7n+130
E) 3n+10

Question

Sam has some quarters, nickels, and dimes. He has 4 more quarters than dimes and 3 more dimes than nickels. If n represents the number of nickels he has, which of the following represents, in cents, the total value of all his coins?
A) 40n+205
B) 40n+130
C) 40n+ 7
D) 7n+130
E) 3n+10

anonymous · Answer

wow... this one is "fun"

anonymous · Answer

if n = nickels and he has 3 more dimes than nickels, then he has (n + 3) dimes, and if he has 4 more quarters than dimes, then he has (n + 3 + 4) quarters, or (n + 7) quarters.
nickels = n
dimes = n + 3
quarters = n + 7

since nickels are worth 5 cents, multiply n x 5
since dimes are worth 10 cents, multiply (n + 3) x 10, and 
since quarters are worth 25 cents, multiply (n + 7) x 25

so 5n +  10(n + 3)  + 25(n + 7) will give you your final answer.