Ivory had some $5-notes and some $2-notes.
711 of the-notes were $5-notes and the rest were $2-notes. After Ivory had spent $1350 worth of $2-notes and
57 of $5-notes, she had
16 of the notes left. Find the number of $5-notes Ivory had left.
| |
$5-notes |
$2-notes |
Total |
Comparing $5-notes
and $2-notes
at first |
7x6 =
42 u |
4x6 =
24 u |
11x6 =
66 u |
| Before |
7x6 =
42 u |
|
6x11 =
66 u |
| Change |
- 5x6 =
- 30 u |
- 675 |
- 5x11 =
- 55 u |
| After |
2x6=
12 u |
24 u - 675 |
1x11 =
11 u |
The total number of notes at first is the repeated. Make the total number of notes the same. LCM of 11 and 6 is 66.
The number of $5-notes is repeated.
Number of $2-notes
= 1350 ÷ 2
= 675
Total number of notes spent = 30 u + 675
30 u + 675 = 55 u
55 u - 30 u = 675
25 u = 675
1 u = 675 ÷ 25 = 27
Number of $5-notes that Ivory had left
= 12 u
= 12 x 27
= 324
Answer(s): 324
