PSLEArchie had 3.2 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 r.
- If r = 14, how much of the rope was not used to make the figure? Leave your answer in meters.
(a)
Total length of rope used
= r + r + r + (2r - 10) + (r + 17)
= r + r + r + 2r + r - 10 + 17
= (6 r + 7) cm
(b)
1 m = 100 cm
3.2 m = 320 cm
Total length of rope used if r = 14
= 6 r + 7
= 6(14) + 7
= 84 + 7
= 91 cm
Total length of rope not used
= 320 - 91
= 229 cm
1 cm = 0.01 m
229 cm = 2.29 m
Answer(s): (a) (6r + 7) cm; (b) 2.29 m