Vanessa had some $100-notes and some $5-notes.
311 of the notes were $100-notes and the rest were $5-notes. After Vanessa had spent $1615 worth of $5-notes and
13 of $100-notes, she had
35 of the notes left. Find the number of $5-notes Vanessa had left.
| |
$100-notes |
$5-notes |
Total |
Comparing $100-notes
and $5-notes
at first |
3x5 =
15 u |
8x5 =
40 u |
11x5 =
55 u |
| Before |
3x5 =
15 u |
|
5x11 =
55 u |
| Change |
- 1x5 =
- 5 u |
- 323 |
- 2x11 =
- 22 u |
| After |
2x5=
10 u |
40 u - 323 |
3x11 =
33 u |
The total number of notes at first is the repeated. Make the total number of notes the same. LCM of 11 and 5 is 55.
The number of $100-notes is repeated.
Number of $5-notes
= 1615 ÷ 5
= 323
Total number of notes spent = 5 u + 323
5 u + 323 = 22 u
22 u - 5 u = 323
17 u = 323
1 u = 323 ÷ 17 = 19
Number of $5-notes that Vanessa had left
= 40 u - 323
= 40 x 19 - 323
= 437
Answer(s): 437
