Victoria had some $100-notes and some $10-notes.
56 of the-notes were $100-notes and the rest were $10-notes. After Victoria had spent $1980 worth of $10-notes and
15 of $100-notes, she had
112 of the notes left. Find the number of $100-notes Victoria had left.
| |
$100-notes |
$10-notes |
Total |
Comparing $100-notes
and $10-notes
at first |
5x2 =
10 u |
1x2 =
2 u |
6x2 =
12 u |
| Before |
5x2 =
10 u |
|
12x1 =
12 u |
| Change |
- 1x2 =
- 2 u |
- 198 |
- 11x1 =
- 11 u |
| After |
4x2=
8 u |
2 u - 198 |
1x1 =
1 u |
The total number of notes at first is the repeated. Make the total number of notes the same. LCM of 6 and 12 is 12.
The number of $100-notes is repeated.
Number of $10-notes
= 1980 ÷ 10
= 198
Total number of notes spent = 2 u + 198
2 u + 198 = 11 u
11 u - 2 u = 198
9 u = 198
1 u = 198 ÷ 9 = 22
Number of $100-notes that Victoria had left
= 8 u
= 8 x 22
= 176
Answer(s): 176
