A piece of ribbon 2900 cm long is cut into 3 parts, B, A and C.
B is 5 times as long as A.
C is 110 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 + 110
Length of B = 5 x (1 u + 110) = 5 u + 550
Total length of B, A and C
= 5 u + 550 + 1 u + 110 + 1 u
= 5 u + 1 u + 1 u + 550 + 110
= 7 u + 660
7 u + 660 = 2900
7 u = 2900 - 660
7 u = 2240
1 u = 2240 ÷ 7 = 320
Length of B longer than A
= 5 u + 550 - (1 u + 110)
= 5 u - 1 u + 550 - 110
= 4 u + 440
= 4 x 320 + 440
= 1280 + 440
= 1720 cm
(b)
Total length of B and C
= 5 u + 550 + 1 u
= 6 u + 550
= 6 x 320 + 550
= 1920 + 550
= 2470 cm
Answer(s): (a) 1720 cm; (b) 2470 cm