The number of safety cones along the road was 55% of the number of trees planted along it. After 79 safety cones and 79 trees were added to the stretch of road, the number of trees became 10% more than the number of safety cones. How many trees were there at first?
|
Safety Cones |
Trees |
Difference |
Before |
11x1 = 11 u |
20x1 = 20 u |
9x1 = 9 u |
Change |
+ 79 |
+ 79 |
|
After |
10x9 = 90 u |
11x9 = 99 u |
1x9 = 9 u |
55% =
55100 =
1120Number of safety cones in the end in percentage = 100%
Number of trees in the end in percentage
= 100% + 10%
= 110%
110% =
110100 =
1110 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 9 and 1 is 9.
Number of safety cones added
= 90 u - 11 u
= 79 u
79 u = 79
1 u = 79 ÷ 79 = 1
Number of trees at first
= 20 u
= 20 x 1
= 20
Answer(s): 20