Question

90 coins in a jar of quarters and nickels. There is a total of $15.10, how many nickels and how many quarters are in the jar?
--so far, I have the 2X2 linear system set up as so:
15.10 = .05n + .25q
90 = .05n + .25q
--is this correct? and how should I solve it, substitution or elimination?
Thanks!

Answer 1

seems correct but not correct to me.

Answer 2

there's something wrong about it.

Answer 3

because u can't solve it like that, u see the coefficients are the same in front of n and q? that makes it unsolvable.

Answer 4

Yes, I see that

Answer 5

which explains why I keep running in circles

Answer 6

lol. sorry, I haven't done these type of questions in ages..

Answer 7

that's fine, at least I have a hint on a different direction. Thank you

Answer 8

your welcome, let me see if I can ask others to help u.

Answer 9

perhaps?:
15.10 = .05n + .25q
90 = n + q
since amount of quarters and nickels would be whole numbers, but money would be decimal

Answer 10

I believe that's it! There are 37 nickels and 53 quarters. Thanks for the nudge in the right direction. Sometimes it's the little things that help.

Answer 11

yeh, that's what I thought but I wasn't too sure but it should work, yeh it looks right to me.

Answer 12

at least I somehow helped lol.

Answer 13

haha, yeah, you have to know what you are doing wrong to fix it.

Answer 14

haha true.

Answer 15

but u also have to be the smart one to know where to fix it.