Shannon had some $100-notes and some $2-notes.
79 of the notes were $100-notes and the rest were $2-notes. After Shannon had spent $504 worth of $2-notes and
27 of $100-notes, she had
711 of the notes left. Find the number of $2-notes Shannon had left.
| |
$100-notes |
$2-notes |
Total |
Comparing $100-notes
and $2-notes
at first |
7x11 =
77 u |
2x11 =
22 u |
9x11 =
99 u |
| Before |
7x11 =
77 u |
|
11x9 =
99 u |
| Change |
- 2x11 =
- 22 u |
- 252 |
- 4x9 =
- 36 u |
| After |
5x11=
55 u |
22 u - 252 |
7x9 =
63 u |
The total number of notes at first is the repeated. Make the total number of notes the same. LCM of 9 and 11 is 99.
The number of $100-notes is repeated.
Number of $2-notes
= 504 ÷ 2
= 252
Total number of notes spent = 22 u + 252
22 u + 252 = 36 u
36 u - 22 u = 252
14 u = 252
1 u = 252 ÷ 14 = 18
Number of $2-notes that Shannon had left
= 22 u - 252
= 22 x 18 - 252
= 144
Answer(s): 144
