A piece of ribbon 3000 cm long is cut into 3 parts, C, A and B.
C is 4 times as long as A.
B is 240 cm shorter than A.
Give the answers in cm.
- How much longer is C than A?
- What is the total length of C and B?
(a)
Choose the shortest length to be 1 u.
Length of B = 1 u
Length of A = 1 u + 240
Length of C = 4 x (1 u + 240) = 4 u + 960
Total length of C, A and B
= 4 u + 960 + 1 u + 240 + 1 u
= 4 u + 1 u + 1 u + 960 + 240
= 6 u + 1200
6 u + 1200 = 3000
6 u = 3000 - 1200
6 u = 1800
1 u = 1800 ÷ 6 = 300
Length of C longer than A
= 4 u + 960 - (1 u + 240)
= 4 u - 1 u + 960 - 240
= 3 u + 720
= 3 x 300 + 720
= 900 + 720
= 1620 cm
(b)
Total length of C and B
= 4 u + 960 + 1 u
= 5 u + 960
= 5 x 300 + 960
= 1500 + 960
= 2460 cm
Answer(s): (a) 1620 cm; (b) 2460 cm