A piece of ribbon 1800 cm long is cut into 3 parts, C, A and B.
C is 3 times as long as A.
B is 280 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 + 280
Length of C = 3 x (1 u + 280) = 3 u + 840
Total length of C, A and B
= 3 u + 840 + 1 u + 280 + 1 u
= 3 u + 1 u + 1 u + 840 + 280
= 5 u + 1120
5 u + 1120 = 1800
5 u = 1800 - 1120
5 u = 680
1 u = 680 ÷ 5 = 136
Length of B shorter than C
= 3 u + 840 - 1 u
= 3 u - 1 u + 840
= 2 u + 840
= 2 x 136 + 840
= 272 + 840
= 1112 cm
(b)
Total length of C and A = 3 u + 840 + 1 u + 280
= 3 u + 1 u + 840 + 280
= 4 x 136 + 1120 = 544 + 1120 = 1664 cm Answer(s): (a) 1112 cm; (b) 1664 cm