Vanessa had some $5-notes and some $10-notes.
47 of the-notes were $5-notes and the rest were $10-notes. After Vanessa had spent $3360 worth of $10-notes and
34 of $5-notes, she had
411 of the notes left. Find the number of $5-notes Vanessa had left.
| |
$5-notes |
$10-notes |
Total |
Comparing $5-notes
and $10-notes
at first |
4x11 =
44 u |
3x11 =
33 u |
7x11 =
77 u |
| Before |
4x11 =
44 u |
|
11x7 =
77 u |
| Change |
- 3x11 =
- 33 u |
- 336 |
- 7x7 =
- 49 u |
| After |
1x11=
11 u |
33 u - 336 |
4x7 =
28 u |
The total number of notes at first is the repeated. Make the total number of notes the same. LCM of 7 and 11 is 77.
The number of $5-notes is repeated.
Number of $10-notes
= 3360 ÷ 10
= 336
Total number of notes spent = 33 u + 336
33 u + 336 = 49 u
49 u - 33 u = 336
16 u = 336
1 u = 336 ÷ 16 = 21
Number of $5-notes that Vanessa had left
= 11 u
= 11 x 21
= 231
Answer(s): 231
