Fiona had some $2-notes and some $50-notes.
311 of the notes were $2-notes and the rest were $50-notes. After Fiona had spent $4500 worth of $50-notes and
23 of $2-notes, she had
23 of the notes left. Find the number of $50-notes Fiona had left.
| |
$2-notes |
$50-notes |
Total |
Comparing $2-notes
and $50-notes
at first |
3x3 =
9 u |
8x3 =
24 u |
11x3 =
33 u |
| Before |
3x3 =
9 u |
|
3x11 =
33 u |
| Change |
- 2x3 =
- 6 u |
- 90 |
- 1x11 =
- 11 u |
| After |
1x3=
3 u |
24 u - 90 |
2x11 =
22 u |
The total number of notes at first is the repeated. Make the total number of notes the same. LCM of 11 and 3 is 33.
The number of $2-notes is repeated.
Number of $50-notes
= 4500 ÷ 50
= 90
Total number of notes spent = 6 u + 90
6 u + 90 = 11 u
11 u - 6 u = 90
5 u = 90
1 u = 90 ÷ 5 = 18
Number of $50-notes that Fiona had left
= 24 u - 90
= 24 x 18 - 90
= 342
Answer(s): 342
