Winnie had some $2-notes and some $5-notes.
35 of the-notes were $2-notes and the rest were $5-notes. After Winnie had spent $1430 worth of $5-notes and
23 of $2-notes, she had
19 of the notes left. Find the number of $2-notes Winnie had left.
| |
$2-notes |
$5-notes |
Total |
Comparing $2-notes
and $5-notes
at first |
3x9 =
27 u |
2x9 =
18 u |
5x9 =
45 u |
| Before |
3x9 =
27 u |
|
9x5 =
45 u |
| Change |
- 2x9 =
- 18 u |
- 286 |
- 8x5 =
- 40 u |
| After |
1x9=
9 u |
18 u - 286 |
1x5 =
5 u |
The total number of notes at first is the repeated. Make the total number of notes the same. LCM of 5 and 9 is 45.
The number of $2-notes is repeated.
Number of $5-notes
= 1430 ÷ 5
= 286
Total number of notes spent = 18 u + 286
18 u + 286 = 40 u
40 u - 18 u = 286
22 u = 286
1 u = 286 ÷ 22 = 13
Number of $2-notes that Winnie had left
= 9 u
= 9 x 13
= 117
Answer(s): 117
