Linda had some $5-notes and some $10-notes.
712 of the notes were $5-notes and the rest were $10-notes. After Linda had spent $1900 worth of $10-notes and
67 of $5-notes, she had
29 of the notes left. Find the number of $10-notes Linda had left.
| |
$5-notes |
$10-notes |
Total |
Comparing $5-notes
and $10-notes
at first |
7x3 =
21 u |
5x3 =
15 u |
12x3 =
36 u |
| Before |
7x3 =
21 u |
|
9x4 =
36 u |
| Change |
- 6x3 =
- 18 u |
- 190 |
- 7x4 =
- 28 u |
| After |
1x3=
3 u |
15 u - 190 |
2x4 =
8 u |
The total number of notes at first is the repeated. Make the total number of notes the same. LCM of 12 and 9 is 36.
The number of $5-notes is repeated.
Number of $10-notes
= 1900 ÷ 10
= 190
Total number of notes spent = 18 u + 190
18 u + 190 = 28 u
28 u - 18 u = 190
10 u = 190
1 u = 190 ÷ 10 = 19
Number of $10-notes that Linda had left
= 15 u - 190
= 15 x 19 - 190
= 95
Answer(s): 95
