The number of safety cones along the road was 70% of the number of trees planted along it. After 77 safety cones and 77 trees were added to the stretch of road, the number of trees became 35% more than the number of safety cones. How many trees were there at first?
|
Safety Cones |
Trees |
Difference |
Before |
7x7 = 49 u |
10x7 = 70 u |
3x7 = 21 u |
Change |
+ 77 |
+ 77 |
|
After |
20x3 = 60 u |
27x3 = 81 u |
7x3 = 21 u |
70% =
70100 =
710Number of safety cones in the end in percentage = 100%
Number of trees in the end in percentage
= 100% + 35%
= 135%
135% =
135100 =
2720 Since the number of safety cones and trees added is the same, the difference in the number of safety cones and trees remains unchanged. LCM of 3 and 7 is 21.
Number of safety cones added
= 60 u - 49 u
= 11 u
11 u = 77
1 u = 77 ÷ 11 = 7
Number of trees at first
= 70 u
= 70 x 7
= 490
Answer(s): 490