15 lamp posts are placed along a road at equal distances. The distance between the third and the seventh lamp post is 20 m.
- What is the distance between 2 lamp posts?
- What is the distance between the first and the last lamp post?
(a)
Number of intervals between the third and the seventh lamp post
= 7 - 3
= 4
Distance between 2 lamp posts
= 20 ÷ 4
= 5 m
(b)
Number of intervals between first and the last lamp post
= 15 - 1
= 14
Distance between the first and the last lamp post
= 14 x 5
= 70 m
Answer(s): (a) 4 m; (b) 70 m