Lamp posts were located at an equal distance of 12 m apart from one another, starting from the beginning of the road. Between every 2 lamp posts, there were 2 plants, planted 4 m apart.
- What was the distance between the first plant and the 6th plant?
- What was the distance between the eighth plant and the fourteenth plant?
- Given that the stretch of road was 76 m, how many plants were there?
Lamp post ↔ plant ↔ plant ↔ Lamp post ↔ plant ↔ plant ↔ Lamp post ↔ plant ↔ plant ↔ Lamp post
(a)
Length of each gap
= 12 ÷ 3
= 4
Distance between first and 6th plant
= 7 intervals
= 7 x 4
= 28 m
(b)
Distance between eighth and fourteenth plant
= 9 intervals
= 9 x 4
= 36 m
(c)
Distance between 2 lamp posts = 12 m
Number of sets of 12 m
= 76 ÷ 12
= 6 r 4
Number of plants at a distance of 4 m
= 4 ÷ 4
= 1
Number of plants
= 6 x 2 + 1
= 13
Answer(s): (a) 28 m; (b) 36 m; (c) 13