A piece of ribbon 3000 cm long is cut into 3 parts, B, C and A.
B is 3 times as long as C.
A is 220 cm shorter than C.
Give the answers in cm.
- How much shorter is A than B?
- What is the total length of B and C?
(a)
Choose the shortest length to be 1 u.
Length of A = 1 u
Length of C = 1 u + 220
Length of B = 3 x (1 u + 220) = 3 u + 660
Total length of B, C and A
= 3 u + 660 + 1 u + 220 + 1 u
= 3 u + 1 u + 1 u + 660 + 220
= 5 u + 880
5 u + 880 = 3000
5 u = 3000 - 880
5 u = 2120
1 u = 2120 ÷ 5 = 424
Length of A shorter than B
= 3 u + 660 - 1 u
= 3 u - 1 u + 660
= 2 u + 660
= 2 x 424 + 660
= 848 + 660
= 1508 cm
(b)
Total length of B and C = 3 u + 660 + 1 u + 220
= 3 u + 1 u + 660 + 220
= 4 x 424 + 880 = 1696 + 880 = 2576 cm Answer(s): (a) 1508 cm; (b) 2576 cm