SOLUTION: I have twice as many nickels as quarters. If the coins are worth $4.90, how many quarters are there?

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Question 159355This question is from textbook
: I have twice as many nickels as quarters. If the coins are worth $4.90, how many quarters are there? This question is from textbook

Found 2 solutions by Alan3354, Earlsdon:
Answer by Alan3354(69443) (Show Source):
You can put this solution on YOUR website!
I have twice as many nickels as quarters. If the coins are worth $4.90, how many quarters are there?
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N = 2Q (twice as many nickels)
5N + 25Q = 490 (total worth)
Sub for N in the 2nd eqn
5*2Q + 25Q = 490
10Q + 25Q = 490
35Q = 490
Q = 14 (# of quarters)
N = 2Q = 28 (# of nickels)
Checking, it totals $4.90.

Answer by Earlsdon(6294) (Show Source):
You can put this solution on YOUR website!
Let N = number of nickels and Q = number of quarters.
1) N = 2Q "I have twice as many nickels as quarters"
2) 0.05N+0.25Q = 4.90 "...the coins are worth $4.90,..."
Substitute the N = 2Q into equation 2) and solve for Q to get the number of quarters.
0.05(2Q)+0.25Q = 4.90 Simplify.
0.35Q = 4.90 Divide both sides by 0.35
Q = 14 This is the number of quarters.
N = 2Q = 2(14) = 28 This is the number of nickels.
Check:
28(0.05)+14(0.25) = 1.40+3.50 = 4.90