Bobby, Japheth and Rael had 144 pens. After Bobby used 21 pens and Japheth used
14 of her pens, Bobby had thrice as many pens left as Japheth. Rael bought another 29 pens, he had twice the number of pens Japheth had left. How many pens did Rael have at first?
| |
Bobby |
Japheth |
Rael |
Total |
| Before |
9 u + 21 |
4 u |
6 u - 29 |
144 |
| Change |
- 21 |
- 1 u |
+ 29 |
|
| After |
9 u |
3 u |
6 u |
|
Comparing Bobby
and Japheth in the end |
3 |
1 |
|
|
Comparing Rael
and Japheth in the end |
|
1 |
2 |
|
Number of pens that Bobby had in the end
= 3 x 3 u
= 9 u
Number of pens that Rael had in the end
= 2 x 3 u
= 6 u
Total number of pens at first
= 9 u + 21 + 4 u + 6 u - 29
= 19 u - 8
19 u - 8 = 144
19 u = 144 + 8
19 u = 152
1 u = 152 ÷ 19 = 8
Number of pens that Rael had at first
= 6 u - 29
= 6 x 8 - 29
= 48 - 29
= 19
Answer(s): 19
