Vanessa had some $1-notes and some $50-notes.
711 of the notes were $1-notes and the rest were $50-notes. After Vanessa had spent $2250 worth of $50-notes and
17 of $1-notes, she had
78 of the notes left. Find the number of $50-notes Vanessa had left.
| |
$1-notes |
$50-notes |
Total |
Comparing $1-notes
and $50-notes
at first |
7x8 =
56 u |
4x8 =
32 u |
11x8 =
88 u |
| Before |
7x8 =
56 u |
|
8x11 =
88 u |
| Change |
- 1x8 =
- 8 u |
- 45 |
- 1x11 =
- 11 u |
| After |
6x8=
48 u |
32 u - 45 |
7x11 =
77 u |
The total number of notes at first is the repeated. Make the total number of notes the same. LCM of 11 and 8 is 88.
The number of $1-notes is repeated.
Number of $50-notes
= 2250 ÷ 50
= 45
Total number of notes spent = 8 u + 45
8 u + 45 = 11 u
11 u - 8 u = 45
3 u = 45
1 u = 45 ÷ 3 = 15
Number of $50-notes that Vanessa had left
= 32 u - 45
= 32 x 15 - 45
= 435
Answer(s): 435
