A piece of ribbon 4500 cm long is cut into 3 parts, B, A and C.
B is 2 times as long as A.
C is 240 cm shorter than A.
Give the answers in cm.
- How much longer is B than A?
- What is the total length of B and C?
(a)
Choose the shortest length to be 1 u.
Length of C = 1 u
Length of A = 1 u + 240
Length of B = 2 x (1 u + 240) = 2 u + 480
Total length of B, A and C
= 2 u + 480 + 1 u + 240 + 1 u
= 2 u + 1 u + 1 u + 480 + 240
= 4 u + 720
4 u + 720 = 4500
4 u = 4500 - 720
4 u = 3780
1 u = 3780 ÷ 4 = 945
Length of B longer than A
= 2 u + 480 - (1 u + 240)
= 2 u - 1 u + 480 - 240
= 1 u + 240
= 1 x 945 + 240
= 945 + 240
= 1185 cm
(b)
Total length of B and C
= 2 u + 480 + 1 u
= 3 u + 480
= 3 x 945 + 480
= 2835 + 480
= 3315 cm
Answer(s): (a) 1185 cm; (b) 3315 cm