A piece of ribbon 4300 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 shorter is C than A?
- What is the total length of A and B?
(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 = 4300
5 u = 4300 - 880
5 u = 3420
1 u = 3420 ÷ 5 = 684
Length of C shorter than A
= 3 u + 660 - 1 u
= 3 u - 1 u + 660
= 2 u + 660
= 2 x 684 + 660
= 1368 + 660
= 2028 cm
(b)
Total length of A and B = 3 u + 660 + 1 u + 220
= 3 u + 1 u + 660 + 220
= 4 x 684 + 880 = 2736 + 880 = 3616 cm Answer(s): (a) 2028 cm; (b) 3616 cm