Lamp posts were located at an equal distance of 15 m apart from one another, starting from the beginning of the road. Between every 2 lamp posts, there were 2 shrubs, planted 5 m apart.
- What was the distance between the first shrub and the 6th shrub?
- What was the distance between the sixth shrub and the twelfth shrub?
- Given that the stretch of road was 105 m, how many shrubs were there?
Lamp post ↔ shrub ↔ shrub ↔ Lamp post ↔ shrub ↔ shrub ↔ Lamp post ↔ shrub ↔ shrub ↔ Lamp post
(a)
Length of each gap
= 15 ÷ 3
= 5
Distance between first and 6th shrub
= 7 intervals
= 7 x 5
= 35 m
(b)
Distance between sixth and twelfth shrub
= 9 intervals
= 9 x 5
= 45 m
(c)
Distance between 2 lamp posts = 15 m
Number of sets of 15 m
= 105 ÷ 15
= 7
Number of shrubs
= 7 x 2
= 14
Answer(s): (a) 35 m; (b) 45 m; (c) 14