Zara had some $50-notes and some $5-notes.
35 of the notes were $50-notes and the rest were $5-notes. After Zara had spent $1760 worth of $5-notes and
13 of $50-notes, she had
49 of the notes left. Find the number of $5-notes Zara had left.
| |
$50-notes |
$5-notes |
Total |
Comparing $50-notes
and $5-notes
at first |
3x9 =
27 u |
2x9 =
18 u |
5x9 =
45 u |
| Before |
3x9 =
27 u |
|
9x5 =
45 u |
| Change |
- 1x9 =
- 9 u |
- 352 |
- 5x5 =
- 25 u |
| After |
2x9=
18 u |
18 u - 352 |
4x5 =
20 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 $50-notes is repeated.
Number of $5-notes
= 1760 ÷ 5
= 352
Total number of notes spent = 9 u + 352
9 u + 352 = 25 u
25 u - 9 u = 352
16 u = 352
1 u = 352 ÷ 16 = 22
Number of $5-notes that Zara had left
= 18 u - 352
= 18 x 22 - 352
= 44
Answer(s): 44
