A piece of ribbon 3200 cm long is cut into 3 parts, B, C and A.
B is 2 times as long as C.
A is 140 cm shorter than C.
Give the answers in cm.
- How much longer is B than C?
- What is the total length of B and A?
(a)
Choose the shortest length to be 1 u.
Length of A = 1 u
Length of C = 1 u + 140
Length of B = 2 x (1 u + 140) = 2 u + 280
Total length of B, C and A
= 2 u + 280 + 1 u + 140 + 1 u
= 2 u + 1 u + 1 u + 280 + 140
= 4 u + 420
4 u + 420 = 3200
4 u = 3200 - 420
4 u = 2780
1 u = 2780 ÷ 4 = 695
Length of B longer than C
= 2 u + 280 - (1 u + 140)
= 2 u - 1 u + 280 - 140
= 1 u + 140
= 1 x 695 + 140
= 695 + 140
= 835 cm
(b)
Total length of B and A
= 2 u + 280 + 1 u
= 3 u + 280
= 3 x 695 + 280
= 2085 + 280
= 2365 cm
Answer(s): (a) 835 cm; (b) 2365 cm