A piece of ribbon 3200 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 = 3200
4 u = 3200 - 660
4 u = 2540
1 u = 2540 ÷ 4 = 635
Length of B longer than A
= 2 u + 440 - (1 u + 220)
= 2 u - 1 u + 440 - 220
= 1 u + 220
= 1 x 635 + 220
= 635 + 220
= 855 cm
(b)
Total length of B and C
= 2 u + 440 + 1 u
= 3 u + 440
= 3 x 635 + 440
= 1905 + 440
= 2345 cm
Answer(s): (a) 855 cm; (b) 2345 cm