A piece of ribbon 4900 cm long is cut into 3 parts, C, A and B.
C is 3 times as long as A.
B is 150 cm shorter than A.
Give the answers in cm.
- How much shorter is B than C?
- What is the total length of C and A?
(a)
Choose the shortest length to be 1 u.
Length of B = 1 u
Length of A = 1 u + 150
Length of C = 3 x (1 u + 150) = 3 u + 450
Total length of C, A and B
= 3 u + 450 + 1 u + 150 + 1 u
= 3 u + 1 u + 1 u + 450 + 150
= 5 u + 600
5 u + 600 = 4900
5 u = 4900 - 600
5 u = 4300
1 u = 4300 ÷ 5 = 860
Length of B shorter than C
= 3 u + 450 - 1 u
= 3 u - 1 u + 450
= 2 u + 450
= 2 x 860 + 450
= 1720 + 450
= 2170 cm
(b)
Total length of C and A = 3 u + 450 + 1 u + 150
= 3 u + 1 u + 450 + 150
= 4 x 860 + 600 = 3440 + 600 = 4040 cm Answer(s): (a) 2170 cm; (b) 4040 cm