Tina had some $100-notes and some $5-notes.
49 of the-notes were $100-notes and the rest were $5-notes. After Tina had spent $3600 worth of $5-notes and
34 of $100-notes, she had
411 of the notes left. Find the number of $100-notes Tina had left.
| |
$100-notes |
$5-notes |
Total |
Comparing $100-notes
and $5-notes
at first |
4x11 =
44 u |
5x11 =
55 u |
9x11 =
99 u |
| Before |
4x11 =
44 u |
|
11x9 =
99 u |
| Change |
- 3x11 =
- 33 u |
- 720 |
- 7x9 =
- 63 u |
| After |
1x11=
11 u |
55 u - 720 |
4x9 =
36 u |
The total number of notes at first is the repeated. Make the total number of notes the same. LCM of 9 and 11 is 99.
The number of $100-notes is repeated.
Number of $5-notes
= 3600 ÷ 5
= 720
Total number of notes spent = 33 u + 720
33 u + 720 = 63 u
63 u - 33 u = 720
30 u = 720
1 u = 720 ÷ 30 = 24
Number of $100-notes that Tina had left
= 11 u
= 11 x 24
= 264
Answer(s): 264
