Tammy had some $10-notes and some $50-notes.
58 of the notes were $10-notes and the rest were $50-notes. After Tammy had spent $4200 worth of $50-notes and
25 of $10-notes, she had
35 of the notes left. Find the number of $50-notes Tammy had left.
| |
$10-notes |
$50-notes |
Total |
Comparing $10-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 |
- 84 |
- 2x8 =
- 16 u |
| After |
3x5=
15 u |
15 u - 84 |
3x8 =
24 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 $10-notes is repeated.
Number of $50-notes
= 4200 ÷ 50
= 84
Total number of notes spent = 10 u + 84
10 u + 84 = 16 u
16 u - 10 u = 84
6 u = 84
1 u = 84 ÷ 6 = 14
Number of $50-notes that Tammy had left
= 15 u - 84
= 15 x 14 - 84
= 126
Answer(s): 126
