# money problem

• Aug 5th 2012, 09:10 AM
rcs
money problem
Mr R coin bank consists of \$10 bills and \$5 bills only. if there 75 bills worth \$ 450, how many \$10 bills are there?
• Aug 5th 2012, 09:11 AM
skeeter
Re: money problem
Quote:

Originally Posted by rcs
Mr R coin bank consists of \$10 bills and \$5 bills only. if there 75 bills worth \$ 450, how many \$10 bills are there?

x = number of \$10 bills

y = number of \$5 bills

now, you set up two equations from the given information ...
• Aug 6th 2012, 07:13 AM
rcs
Re: money problem
please correct me if im wrong:

10x + 5y = 450
75( x+ y) = 450
• Aug 6th 2012, 07:35 AM
skeeter
Re: money problem
Quote:

Originally Posted by rcs
please correct me if im wrong:

10x + 5y = 450 this equation is ok ...

75( x+ y) = 450 this equation is incorrect ... x is the number of \$10 bills , y is the number of \$5 bills, the total number of bills is 75

... fix it.
• Aug 6th 2012, 08:05 AM
rcs
Re: money problem
Quote:

Originally Posted by skeeter
... fix it.

10x + 5y = 450
x + y = 75
• Aug 6th 2012, 08:10 AM
skeeter
Re: money problem
Quote:

Originally Posted by rcs
10x + 5y = 450
x + y = 75

good ... solve the system.
• Aug 6th 2012, 08:30 AM
rcs
Re: money problem
Quote:

Originally Posted by skeeter
good ... solve the system.

thank you skeeter great Mentor!