how many of each?

Question

there is a total of 3.45 in change. And there are 9 more nickels than quarters. How many of each?

Answer 1

Q = number of quarters at 0.25 each

 

N  = number of nickels at 0.05 each

 

N  = 9 + Q

 

3.45 = (0.25)Q + (0.05)N = (0.25)Q + (0.05)(9 + Q)

 

3.45 = (0.25 + 0.05)Q + (0.05)(9)

 

3 = 0.3Q

 

Q = 3/0.3 = 10

 

There are 10 quarters.

 

There are 9 + 10 = 19 nickels.

Answer 2

$3.45 = 345 c

 

Let x be the number of quarters, then

 

345 = 25x + 5(x+9) 

345 = 25x + 5x + 45

345 - 45 = 30x

300 = 30x

300/30 = x

10 = x

 There are 10 quarters and 10 + 9 = 19 nickels.