SOLUTION: john has twice the number of quarters as dimes. the amount of money in$1.80. find the number of dimes

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Question 736645: john has twice the number of quarters as dimes. the amount of money in$1.80. find the number of dimes
Found 3 solutions by stanbon, josmiceli, lynnlo:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
john has twice the number of quarters as dimes. the amount of money in$1.80. find the number of dimes
Equations:
q = 2dan
10d + 25q = 180 cents
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Substitute for "q" and solve for "d":
10d + 25(2d) = 180
10d + 50d = 180
60d = 180
d = 3 (# of dimes)
------
Solve for "q":
q = 2d
q = 2*3 = 6 (# of quarters)
============================
Cheers,
Stan H.
=============

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
(1) +10d+%2B+25q+=+180+ ( in cents )
(2) +q+=+2d+
--------------
(1) +10d+%2B+25q+=+180+
(2) +d+=+q%2F2+
Substitute (2) into (1)
(1) +10%2A%28q%2F2%29+%2B+25q+=+180+
(1) +5q+%2B+25q+=+180+
(1) +30q+=+180+
(1) +q+=+6+
and
(2) +d+=+q%2F2+
(2) +d+=+6%2F2+
(2) +d+=+3+
There are 3 dimes
check:
(1) +10%2A3+%2B+25%2A6+=+180+
(1) +30+%2B+150+=+180+
(1) +180+=+180+
OK

Answer by lynnlo(4176) About Me  (Show Source):
You can put this solution on YOUR website!
TOTAL===============$1.80
DIMES===========3==.30
QUARTERS========6==$1.50
=========================
===================$1.80