A piece of ribbon 1500 cm long is cut into 3 parts, B, A and C.
B is 3 times as long as A.
C is 150 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 + 150
Length of B = 3 x (1 u + 150) = 3 u + 450
Total length of B, A and C
= 3 u + 450 + 1 u + 150 + 1 u
= 3 u + 1 u + 1 u + 450 + 150
= 5 u + 600
5 u + 600 = 1500
5 u = 1500 - 600
5 u = 900
1 u = 900 ÷ 5 = 180
Length of B longer than A
= 3 u + 450 - (1 u + 150)
= 3 u - 1 u + 450 - 150
= 2 u + 300
= 2 x 180 + 300
= 360 + 300
= 660 cm
(b)
Total length of B and C
= 3 u + 450 + 1 u
= 4 u + 450
= 4 x 180 + 450
= 720 + 450
= 1170 cm
Answer(s): (a) 660 cm; (b) 1170 cm