A piece of ribbon 2400 cm long is cut into 3 parts, C, A and B.
C is 2 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 = 2 x (1 u + 280) = 2 u + 560
Total length of C, A and B
= 2 u + 560 + 1 u + 280 + 1 u
= 2 u + 1 u + 1 u + 560 + 280
= 4 u + 840
4 u + 840 = 2400
4 u = 2400 - 840
4 u = 1560
1 u = 1560 ÷ 4 = 390
Length of B shorter than C
= 2 u + 560 - 1 u
= 2 u - 1 u + 560
= 1 u + 560
= 1 x 390 + 560
= 390 + 560
= 950 cm
(b)
Total length of C and A = 2 u + 560 + 1 u + 280
= 2 u + 1 u + 560 + 280
= 3 x 390 + 840 = 1170 + 840 = 2010 cm Answer(s): (a) 950 cm; (b) 2010 cm