Nicole had some $2-notes and some $10-notes.
58 of the-notes were $2-notes and the rest were $10-notes. After Nicole had spent $3410 worth of $10-notes and
15 of $2-notes, she had
49 of the notes left. Find the number of $2-notes Nicole had left.
| |
$2-notes |
$10-notes |
Total |
Comparing $2-notes
and $10-notes
at first |
5x9 =
45 u |
3x9 =
27 u |
8x9 =
72 u |
| Before |
5x9 =
45 u |
|
9x8 =
72 u |
| Change |
- 1x9 =
- 9 u |
- 341 |
- 5x8 =
- 40 u |
| After |
4x9=
36 u |
27 u - 341 |
4x8 =
32 u |
The total number of notes at first is the repeated. Make the total number of notes the same. LCM of 8 and 9 is 72.
The number of $2-notes is repeated.
Number of $10-notes
= 3410 ÷ 10
= 341
Total number of notes spent = 9 u + 341
9 u + 341 = 40 u
40 u - 9 u = 341
31 u = 341
1 u = 341 ÷ 31 = 11
Number of $2-notes that Nicole had left
= 36 u
= 36 x 11
= 396
Answer(s): 396
