A piece of ribbon 4500 cm long is cut into 3 parts, C, B and A.
C is 3 times as long as B.
A is 240 cm shorter than B.
Give the answers in cm.
- How much longer is C than B?
- What is the total length of C and A?
(a)
Choose the shortest length to be 1 u.
Length of A = 1 u
Length of B = 1 u + 240
Length of C = 3 x (1 u + 240) = 3 u + 720
Total length of C, B and A
= 3 u + 720 + 1 u + 240 + 1 u
= 3 u + 1 u + 1 u + 720 + 240
= 5 u + 960
5 u + 960 = 4500
5 u = 4500 - 960
5 u = 3540
1 u = 3540 ÷ 5 = 708
Length of C longer than B
= 3 u + 720 - (1 u + 240)
= 3 u - 1 u + 720 - 240
= 2 u + 480
= 2 x 708 + 480
= 1416 + 480
= 1896 cm
(b)
Total length of C and A
= 3 u + 720 + 1 u
= 4 u + 720
= 4 x 708 + 720
= 2832 + 720
= 3552 cm
Answer(s): (a) 1896 cm; (b) 3552 cm