Question

You took 75 coins to the bank. The coins were a mix of pennies and dimes. If the teller told you there was $4.80 in the pile, how many dimes did you have?

5
15
30
45

Answer 1

45

Answer 2

45 * $0.10 = 4.50
the remaining 30 cents is 30 coins so they are pennies

Answer 3

so is it 45 or 30?

Answer 4

its 45 dimes

Answer 5

It would be beneficial to create a system of equations
x= penny, y=dime
1.) x+y=75
2.) .01x+.1y=4.80
I preferably dont like decimals so multiply all the terms of the second equation by 100 and get x+10y=480, and then solve for x and get x=480-10y.Then by using substitution you'll get 480-10y+y=75 and combine like terns to get 9y=405 and y=45. So there are 45 dimes.