Xandra had some $10-notes and some $1-notes.
511 of the notes were $10-notes and the rest were $1-notes. After Xandra had spent $897 worth of $1-notes and
25 of $10-notes, she had
38 of the notes left. Find the number of $1-notes Xandra had left.
| |
$10-notes |
$1-notes |
Total |
Comparing $10-notes
and $1-notes
at first |
5x8 =
40 u |
6x8 =
48 u |
11x8 =
88 u |
| Before |
5x8 =
40 u |
|
8x11 =
88 u |
| Change |
- 2x8 =
- 16 u |
- 897 |
- 5x11 =
- 55 u |
| After |
3x8=
24 u |
48 u - 897 |
3x11 =
33 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 $10-notes is repeated.
Number of $1-notes
= 897 ÷ 1
= 897
Total number of notes spent = 16 u + 897
16 u + 897 = 55 u
55 u - 16 u = 897
39 u = 897
1 u = 897 ÷ 39 = 23
Number of $1-notes that Xandra had left
= 48 u - 897
= 48 x 23 - 897
= 207
Answer(s): 207
