Question

A waiter earned $31 in tips in an hour. He was paid in $1 bills and $5 bills. Use a model to determine how many $5 bills he received if he received a total of 15 bills.

Answer 1

well let F = the number of five dollar bills
O = the number of one dollar bills

the total number of bills is 15

so F + O= 15

now for the value of the bills is $31

then 5F +O = 31

you have 2 equations in 2 unknowns that you now need to solve to find F

Answer 2

let a = the number of 1 dollar bills, let b = the number of five dollar bills.

so \[31 = a+5b\] and \[a + b = 15\]

Answer 3

solve the second equation for a and then plug the result into the first equation

Answer 4

exactly the same...

you can solve by substitution or elimination

Answer 5

yup, the same :)

Answer 6

yep... thats substitution method and that works

Answer 7

i dont get it can you break it down a little..please

Answer 8

"total of 15 bills " -> O + F = 15

Answer 9

well you have 15 notes made up of $5 and $ 1

so you say F + O = 15

does that make sense

Answer 10

@kardaja Hello...!!

Answer 11

you also need to set up an equation for the value of the notes

so 5F + O = 31

or 5 times the number of five dollar bills + 1 times the number of one dollar bills has a total value of $31.

Answer 12

Okay. Thank You.

Answer 13

No of $5 bills No of $1 bills
1 26 NO
2 21 NO
3 16 NO
4 11 YES!
5 6 No need to do more
(This only works because it's small set)

Answer 14

Let x= one dollar bills and y= $5 bills
x+y=15
x+5y=31
4y=16
y=4 ($5 bills)=$20
x=11 ($1 bills)= 11
15bills $31

Answer 15

he has 4 bills