A piece of ribbon 4200 cm long is cut into 3 parts, B, A and C.
B is 2 times as long as A.
C is 220 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 + 220
Length of B = 2 x (1 u + 220) = 2 u + 440
Total length of B, A and C
= 2 u + 440 + 1 u + 220 + 1 u
= 2 u + 1 u + 1 u + 440 + 220
= 4 u + 660
4 u + 660 = 4200
4 u = 4200 - 660
4 u = 3540
1 u = 3540 ÷ 4 = 885
Length of B longer than A
= 2 u + 440 - (1 u + 220)
= 2 u - 1 u + 440 - 220
= 1 u + 220
= 1 x 885 + 220
= 885 + 220
= 1105 cm
(b)
Total length of B and C
= 2 u + 440 + 1 u
= 3 u + 440
= 3 x 885 + 440
= 2655 + 440
= 3095 cm
Answer(s): (a) 1105 cm; (b) 3095 cm