A cash register contains only five dollar and ten dollar bills. It contains twice as many five's as ten's and the total amount of money in the cash register is 580 dollars. How many ten's are in the cash register?

Question

dn_20 · Answer

So x = 5, y = 10, z= # of 5's have, and a= # of 10's have
2xz +ya =580
2 (5) z + 10a = 580
10z +10a = 580
10(z+a) = 580
z+a =58
We have twice as many fives than tens, so
z = 2a
Substitution Property of Equality
2a +a = 58
3a = 58
a = 19.333
So z= 38.667
So we have 19 bill of 10's and 38 bill of 5's, but the last one? 1/3 for 10's and 2/3 for 5's, so 19 1/3 bill of 10's and 38 2/3 bill of 5's

dn_20 · Answer

Sorry, I not totally sure if I did it right. But I hope that I'm right since I checked many time before I sent this.

anonymous · Answer

what if the money was 680 would it be the same formula

dn_20 · Answer

Yeah

dn_20 · Answer

The answers is crazy, since the bills cannot be in fraction

anonymous · Answer

So if its 680, how many 10s would there be?

dn_20 · Answer

The number of 10s will be 22.667, while the 5s are 45.333