Ivan was fixing a jigsaw puzzle. By the fourth day, the number of pieces he fixed was 20% of the number of pieces unfixed. After another 5 days, he fixed another 686 pieces and the number of unfixed pieces he was left with was 10% of the number of pieces fixed. How many pieces were left unfixed?
| |
Fixed |
Unfixed |
Total |
| Before |
1x11 =
11 u |
5x11 =
55 u |
6x11 =
66 u |
| Change |
+ 686 |
- 686 |
|
| After |
10x6 =
60 u |
1x6 =
6 u |
11x6 =
66 u |
20% =
20100 =
15 10% =
20100 =
110 Since this is a jigsaw puzzle, there is no change in the total number of jigsaw pieces. Make the total number of jigsaw pieces the same. LCM of 6 and 11 is 66.
Number of additional pieces of jigsaw puzzle that Ivan fixed
= 60 u - 11 u
= 49 u
49 u = 686
1 u = 686 ÷ 49 = 14
Number of pieces that were left unfixed
= 6 u
= 6 x 14
= 84
Answer(s): 84
