Peggy had three times as many quarters as nickels. She had $1.60 in all. How many nickels and how many quarters did she have?
The equation for the problem is:
2007-01-17 05:00:52 · 5 answers · asked by texas_diamond_diva 1 in Science & Mathematics ➔ Mathematics
q=3n
25q + 5n = 160
replacing q by 3n in 2nd equation
75n+5n = 160
80n = 160
n = 2
q= 6
2007-01-17 05:25:44 · answer #1 · answered by catarthur 6 · 0⤊ 0⤋
.05x + 3(.25x) = 1.60
.05c + .75x = 1.60
.8x = 1.60
.8x / .8 = 1.60 / .8
x = 2
The answer is x = 2
Insert the x value into the equation
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0.05x + 3(.25x) = 1.60
0.05(2) + 3[.25(2)] = 1.60
.1 + 3[.5] = 1.60
.1 + 1.5 = 1.60
1.60 = 1.60
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.1 = 2 nickles
1.5 = 6 quarters
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2007-01-17 07:00:54 · answer #2 · answered by SAMUEL D 7 · 0⤊ 0⤋
Let X = # of quarters
Let Y = # of nickels
3Y = X
.25X + .05Y = 1.60
Thus, since X = 3Y...
.25(3Y) + .05Y = 1.60
.75Y + .05Y = 1.60
.80Y = 1.60
Y = 2
Thus, X = 6
This is a system of equations, there are two. Two equations, two unknowns.
2007-01-17 05:08:28 · answer #3 · answered by Anonymous · 0⤊ 0⤋
nickles=x
quarter=y
y=3x
5x+25y=160
2007-01-17 05:05:08 · answer #4 · answered by well thts it...... 3 · 0⤊ 0⤋
n = 3q
0.05n + 0.25q=1.6
0.05(3q) + 0.25q = 1.6
0.15q + 0.25q = 1.6
0.4q=1.6 => q=4
n = 12
2007-01-17 05:20:19 · answer #5 · answered by Anonymous · 0⤊ 0⤋