Ivan has 90% as many pens as Vincent. If Ivan gives away 25% of the pens and Vincent gives away 60% of his pens, they will have 172 pens altogether. How many pens do the two of them have?
| |
Ivan |
Vincent |
Total |
Comparing Ivan
and Vincent at first |
9x4 =
36 u |
10x4 =
40 u |
|
| Before |
4x9 =
36 u |
5x8 =
40 u |
|
| Change |
- 1x9 =
- 9 u |
- 3x8 =
- 24 u |
|
| After |
3x9 =
27 u |
2x8 =
16 u |
172 |
90% =
90100 =
910 25% =
25100 =
14 60% =
60100 =
35 The number of pens that Ivan has at first is repeated. Make the number of pens that Ivan has the same. LCM of 9 and 4 is 36 u.
The number of pens that Vincent has at first is repeated. Make the number of pens that Vincent has the same. LCM of 10 and 5 is 40 u.
Number of pens in the end
= 27 u + 16 u
= 43 u
43 u = 172
1 u = 172 ÷ 43 = 4
Total number of pens that the two of them have
= 36 u + 40 u
= 76 u
= 76 x 4
= 304
Answer(s): 304
