Elyse had some $5-notes and some $50-notes.
58 of the notes were $5-notes and the rest were $50-notes. After Elyse had spent $7700 worth of $50-notes and
25 of $5-notes, she had
25 of the notes left. Find the number of $50-notes Elyse had left.
| |
$5-notes |
$50-notes |
Total |
Comparing $5-notes
and $50-notes
at first |
5x5 =
25 u |
3x5 =
15 u |
8x5 =
40 u |
| Before |
5x5 =
25 u |
|
5x8 =
40 u |
| Change |
- 2x5 =
- 10 u |
- 154 |
- 3x8 =
- 24 u |
| After |
3x5=
15 u |
15 u - 154 |
2x8 =
16 u |
The total number of notes at first is the repeated. Make the total number of notes the same. LCM of 8 and 5 is 40.
The number of $5-notes is repeated.
Number of $50-notes
= 7700 ÷ 50
= 154
Total number of notes spent = 10 u + 154
10 u + 154 = 24 u
24 u - 10 u = 154
14 u = 154
1 u = 154 ÷ 14 = 11
Number of $50-notes that Elyse had left
= 15 u - 154
= 15 x 11 - 154
= 11
Answer(s): 11
