PSLEElijah had 3.6 m of rope. He used some of it to make the figure as shown.
- How much of the rope did Andy use to make the figure? Leave your answer in the simplest form in terms of b.
- If b = 21, how much of the rope was not used to make the figure? Leave your answer in meters.
(a)
Total length of rope used
= b + b + b + (3b - 9) + (b + 17)
= b + b + b + 3b + b - 9 + 17
= (7 b + 8) cm
(b)
1 m = 100 cm
3.6 m = 360 cm
Total length of rope used if b = 21
= 7 b + 8
= 7(21) + 8
= 147 + 8
= 155 cm
Total length of rope not used
= 360 - 155
= 205 cm
1 cm = 0.01 m
205 cm = 2.05 m
Answer(s): (a) (7b + 8) cm; (b) 2.05 m