# Math Help - Electronic bank teller question

1. ## Electronic bank teller question

An electronic bank teller registered $775 after it had counted 120 notes and$975 after it had counted 160 notes.
Find a formula for the sum registered, in terms of the number of notes counted.
Was there a sum already on the register when counting began?
If so, how much?

2. Let Y = sum registered

N = Number of notes counted

a = value of notes

S= sum in the register when counting began...

$775 = 120a+s$

$975=160a+s$

then.....

3. Thanks so much.
I had this question in my worksheet as well.
I ended up getting it right.

4. Thanks for all of your help.