Jim has a total of 50 coins. Some are nickles and some are dimes. Altogether he has $4.15. How many dimes doe he have? How many nickels?
2007-12-03 05:45:27 · 3 answers · asked by Jessica G 1 in Science & Mathematics ➔ Mathematics
Let N be number of nickels
Let D be number of dimes
You have two equations:
N + D = 50
5N + 10D = 415
Now you can easily solve by elimination or substitution.
For example, solve for N:
N = 50 - D
Substitute into the second equation:
5(50 - D) + 10D = 415
250 - 5D + 10D = 415
250 + 5D = 415
5D = 165
D = 165/5
D = 33
N = 50 - D
N = 50 - 33
N = 17
33 dimes and 17 nickels.
As a double-check:
1) We have 50 coins
2) 33 dimes = $3.30, 17 nickels = $0.85. All together that is $4.15.
2007-12-03 05:50:38 · answer #1 · answered by Puzzling 7 · 0⤊ 0⤋
17 nickels, 33 dimes
2007-12-03 05:51:04 · answer #2 · answered by Luke 2 · 0⤊ 0⤋
x= sort of 10$ expenditures y=sort of 20$expenditures x-y=21 10x + 20y =630 remedy the 1st question for y: x-21=y positioned the value of y into the 2d equation and remedy for x: 10x +20(x-21)=630 30x -420 =630 30x=1050 x=35 on condition that x (sort of 10$ expenditures) is 35 there must be (35-21) or 14 20 greenback expenditures
2016-10-19 00:10:51 · answer #3 · answered by ? 3 · 0⤊ 0⤋