A piece of ribbon 1800 cm long is cut into 3 parts, C, A and B.
C is 2 times as long as A.
B is 160 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 + 160
Length of C = 2 x (1 u + 160) = 2 u + 320
Total length of C, A and B
= 2 u + 320 + 1 u + 160 + 1 u
= 2 u + 1 u + 1 u + 320 + 160
= 4 u + 480
4 u + 480 = 1800
4 u = 1800 - 480
4 u = 1320
1 u = 1320 ÷ 4 = 330
Length of B shorter than C
= 2 u + 320 - 1 u
= 2 u - 1 u + 320
= 1 u + 320
= 1 x 330 + 320
= 330 + 320
= 650 cm
(b)
Total length of C and A = 2 u + 320 + 1 u + 160
= 2 u + 1 u + 320 + 160
= 3 x 330 + 480 = 990 + 480 = 1470 cm Answer(s): (a) 650 cm; (b) 1470 cm
