kandi has $ 2.65 in nickels and dimes. If she has 40 coins in all, how many nickels does she have?
2006-09-12 08:38:23 · 6 answers · asked by ddd d 1 in Science & Mathematics ➔ Mathematics
27
2006-09-12 08:45:40 · answer #1 · answered by Leader Desslok 4 · 0⤊ 0⤋
let us convert them to cents first :
nickel = 5 cents
dime = 10 cents
total = 265 cents
if all were nickel, there would be 53 (265/5) coins...but there are only 40... extra 13 coins must be made into dimes...(since 2 nickels = dime)
hence 13 dimes & 27 nickels
we can solve it algebraically easily: let n be number of nickels and d number of dimes, then
5n + 10 d = 265
n + d = 40
hence 5(40-d) + 10 d = 265 or 200+5d=265 or d=13 and n=27
2006-09-12 15:46:56 · answer #2 · answered by m s 3 · 0⤊ 0⤋
Set up a system of equations:
x = nickels
y = dimes
Given:
x + y = 40
5x + 10y = 265
y = 40 - x
Substitute this into 2nd equation:
5x + 10(40 - x) = 265
5x + 400 - 10x = 265
-5x = -135
5x = 135
x = 27
2006-09-12 15:47:30 · answer #3 · answered by Professor 3 · 0⤊ 0⤋
.05n + .10d = 2.65
5n + 10d = 265
5n + 10d = 265
n + d = 40
Multiply bottom by -5
5n + 10d = 265
-5n - 5d = -200
5d = 65
d = 13
n + d = 40
n + 13 = 40
n = 27
27 nickles
13 dimes
ANS : 27 nickles
2006-09-12 16:44:58 · answer #4 · answered by Sherman81 6 · 0⤊ 0⤋
I am not going to do your homework for you!
2006-09-12 15:43:44 · answer #5 · answered by Anonymous · 0⤊ 0⤋
Answer:You tell us
2006-09-12 15:44:25 · answer #6 · answered by Anonymous · 0⤊ 0⤋