Dana had some $50-notes and some $2-notes.
79 of the-notes were $50-notes and the rest were $2-notes. After Dana had spent $832 worth of $2-notes and
57 of $50-notes, she had
211 of the notes left. Find the number of $50-notes Dana had left.
| |
$50-notes |
$2-notes |
Total |
Comparing $50-notes
and $2-notes
at first |
7x11 =
77 u |
2x11 =
22 u |
9x11 =
99 u |
| Before |
7x11 =
77 u |
|
11x9 =
99 u |
| Change |
- 5x11 =
- 55 u |
- 416 |
- 9x9 =
- 81 u |
| After |
2x11=
22 u |
22 u - 416 |
2x9 =
18 u |
The total number of notes at first is the repeated. Make the total number of notes the same. LCM of 9 and 11 is 99.
The number of $50-notes is repeated.
Number of $2-notes
= 832 ÷ 2
= 416
Total number of notes spent = 55 u + 416
55 u + 416 = 81 u
81 u - 55 u = 416
26 u = 416
1 u = 416 ÷ 26 = 16
Number of $50-notes that Dana had left
= 22 u
= 22 x 16
= 352
Answer(s): 352
