A piece of ribbon 2500 cm long is cut into 3 parts, A, B and C.
A is 3 times as long as B.
C is 220 cm shorter than B.
Give the answers in cm.
- How much longer is A than B?
- What is the total length of A and C?
(a)
Choose the shortest length to be 1 u.
Length of C = 1 u
Length of B = 1 u + 220
Length of A = 3 x (1 u + 220) = 3 u + 660
Total length of A, B and C
= 3 u + 660 + 1 u + 220 + 1 u
= 3 u + 1 u + 1 u + 660 + 220
= 5 u + 880
5 u + 880 = 2500
5 u = 2500 - 880
5 u = 1620
1 u = 1620 ÷ 5 = 324
Length of A longer than B
= 3 u + 660 - (1 u + 220)
= 3 u - 1 u + 660 - 220
= 2 u + 440
= 2 x 324 + 440
= 648 + 440
= 1088 cm
(b)
Total length of A and C
= 3 u + 660 + 1 u
= 4 u + 660
= 4 x 324 + 660
= 1296 + 660
= 1956 cm
Answer(s): (a) 1088 cm; (b) 1956 cm