A piece of ribbon 1700 cm long is cut into 3 parts, B, C and A.
B is 3 times as long as C.
A is 110 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 + 110
Length of B = 3 x (1 u + 110) = 3 u + 330
Total length of B, C and A
= 3 u + 330 + 1 u + 110 + 1 u
= 3 u + 1 u + 1 u + 330 + 110
= 5 u + 440
5 u + 440 = 1700
5 u = 1700 - 440
5 u = 1260
1 u = 1260 ÷ 5 = 252
Length of B longer than C
= 3 u + 330 - (1 u + 110)
= 3 u - 1 u + 330 - 110
= 2 u + 220
= 2 x 252 + 220
= 504 + 220
= 724 cm
(b)
Total length of B and A
= 3 u + 330 + 1 u
= 4 u + 330
= 4 x 252 + 330
= 1008 + 330
= 1338 cm
Answer(s): (a) 724 cm; (b) 1338 cm