Jane had some $100-notes and some $5-notes.
512 of the-notes were $100-notes and the rest were $5-notes. After Jane had spent $1275 worth of $5-notes and
35 of $100-notes, she had
711 of the notes left. Find the number of $100-notes Jane had left.
| |
$100-notes |
$5-notes |
Total |
Comparing $100-notes
and $5-notes
at first |
5x11 =
55 u |
7x11 =
77 u |
12x11 =
132 u |
| Before |
5x11 =
55 u |
|
11x12 =
132 u |
| Change |
- 3x11 =
- 33 u |
- 255 |
- 4x12 =
- 48 u |
| After |
2x11=
22 u |
77 u - 255 |
7x12 =
84 u |
The total number of notes at first is the repeated. Make the total number of notes the same. LCM of 12 and 11 is 132.
The number of $100-notes is repeated.
Number of $5-notes
= 1275 ÷ 5
= 255
Total number of notes spent = 33 u + 255
33 u + 255 = 48 u
48 u - 33 u = 255
15 u = 255
1 u = 255 ÷ 15 = 17
Number of $100-notes that Jane had left
= 22 u
= 22 x 17
= 374
Answer(s): 374
