A piece of ribbon 1400 cm long is cut into 3 parts, B, A and C.
B is 3 times as long as A.
C is 220 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 + 220
Length of B = 3 x (1 u + 220) = 3 u + 660
Total length of B, A and C
= 3 u + 660 + 1 u + 220 + 1 u
= 3 u + 1 u + 1 u + 660 + 220
= 5 u + 880
5 u + 880 = 1400
5 u = 1400 - 880
5 u = 520
1 u = 520 ÷ 5 = 104
Length of B longer than A
= 3 u + 660 - (1 u + 220)
= 3 u - 1 u + 660 - 220
= 2 u + 440
= 2 x 104 + 440
= 208 + 440
= 648 cm
(b)
Total length of B and C
= 3 u + 660 + 1 u
= 4 u + 660
= 4 x 104 + 660
= 416 + 660
= 1076 cm
Answer(s): (a) 648 cm; (b) 1076 cm