Jeremy placed 25 pins in a row from one to the other end of a bulletin board at equal distance apart as shown in the diagram. The distance between the first and last pin was 96 cm.
- What was the distance between the first and eighth pin?
- Jeremy decided to remove 8 pins and rearrange the remaining pins at a new equal spacing. What was the new distance of each spacing?
(a)
Number of intervals is 1 less than the number of pins.
Number of intervals in 25 pins
= 25 - 1
= 24
24 intervals = 96 cm
1 interval = 96 ÷ 24 = 4 cm
Number of intervals between the first and the eighth pin = 7
Distance between the first and the eighth pin
= 7 x 4
= 28 cm
(b)
Number of pins left
= 25 - 8
= 17
Number of intervals
= 17 - 1
= 16
New distance of each spacing
= 96 ÷ 16
= 6 cm
Answer(s): (a) 28 cm; (b) 6 cm