Yen had some $50-notes and some $1-notes.
611 of the-notes were $50-notes and the rest were $1-notes. After Yen had spent $280 worth of $1-notes and
56 of $50-notes, she had
27 of the notes left. Find the number of $50-notes Yen had left.
| |
$50-notes |
$1-notes |
Total |
Comparing $50-notes
and $1-notes
at first |
6x7 =
42 u |
5x7 =
35 u |
11x7 =
77 u |
| Before |
6x7 =
42 u |
|
7x11 =
77 u |
| Change |
- 5x7 =
- 35 u |
- 280 |
- 5x11 =
- 55 u |
| After |
1x7=
7 u |
35 u - 280 |
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 7 is 77.
The number of $50-notes is repeated.
Number of $1-notes
= 280 ÷ 1
= 280
Total number of notes spent = 35 u + 280
35 u + 280 = 55 u
55 u - 35 u = 280
20 u = 280
1 u = 280 ÷ 20 = 14
Number of $50-notes that Yen had left
= 7 u
= 7 x 14
= 98
Answer(s): 98
