Question 1027172: Bob and Regina have 36 coins that are nickels and dimes. If the value of the coins is $2.90 how many coins of each type do they have? Answer by addingup(3677) (Show Source):
You can put this solution on YOUR website! n+d = 36 subtract d from both sides
n = 36-d We'll use this value for n next
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
0.05n+0.10d = 2.90 substitute for n
0.05(36-d)+0.10d = 2.90
1.80-0.05d+0.10d = 2.90
0.05d = 1.10
d = 22
n = 36-22 = 14
~~~~~~~~~~~~~~~~~~~~~~~
Check:
d= 22 = 2.20
n= 14 = 0.70
. . . .------
Total . :2.90 Correct