SOLUTION: Jeff has $3.15 made up of nickels and dimes. If he has five times as many nickels as dimes, how many dimes does he have?

Algebra ->  Linear-equations -> SOLUTION: Jeff has $3.15 made up of nickels and dimes. If he has five times as many nickels as dimes, how many dimes does he have?      Log On


   

Question 462494: Jeff has $3.15 made up of nickels and dimes. If he has five times as many nickels as dimes, how many dimes does he have?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +n+ = number of nickels
Let +d+ = number of dimes
given:
(1) +5n+%2B+10d+=+315+ (in cents)
(2) +n+=+5d+
-----------------
Substitute (2) into (1)
(1) +5%2A%285d%29+%2B+10d+=+315+
(1) +25d+%2B+10d+=+315+
(1) +35d+=+315+
(1) +d+=+9+
and
(2) +n+=+5d+
(2) +n+=+45+
Jeff has 9 dimes
check:
(1) +5n+%2B+10d+=+315+
(1) +5%2A45+%2B+10%2A9+=+315+
(1) +225+%2B+90+=+315+
(1) +315+=+315+
OK