Gem had some $50-notes and some $1-notes.
56 of the-notes were $50-notes and the rest were $1-notes. After Gem had spent $110 worth of $1-notes and
15 of $50-notes, she had
29 of the notes left. Find the number of $50-notes Gem had left.
| |
$50-notes |
$1-notes |
Total |
Comparing $50-notes
and $1-notes
at first |
5x3 =
15 u |
1x3 =
3 u |
6x3 =
18 u |
| Before |
5x3 =
15 u |
|
9x2 =
18 u |
| Change |
- 1x3 =
- 3 u |
- 110 |
- 7x2 =
- 14 u |
| After |
4x3=
12 u |
3 u - 110 |
2x2 =
4 u |
The total number of notes at first is the repeated. Make the total number of notes the same. LCM of 6 and 9 is 18.
The number of $50-notes is repeated.
Number of $1-notes
= 110 ÷ 1
= 110
Total number of notes spent = 3 u + 110
3 u + 110 = 14 u
14 u - 3 u = 110
11 u = 110
1 u = 110 ÷ 11 = 10
Number of $50-notes that Gem had left
= 12 u
= 12 x 10
= 120
Answer(s): 120
