A piece of ribbon 5000 cm long is cut into 3 parts, B, C and A.
B is 3 times as long as C.
A is 240 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 + 240
Length of B = 3 x (1 u + 240) = 3 u + 720
Total length of B, C and A
= 3 u + 720 + 1 u + 240 + 1 u
= 3 u + 1 u + 1 u + 720 + 240
= 5 u + 960
5 u + 960 = 5000
5 u = 5000 - 960
5 u = 4040
1 u = 4040 ÷ 5 = 808
Length of A shorter than B
= 3 u + 720 - 1 u
= 3 u - 1 u + 720
= 2 u + 720
= 2 x 808 + 720
= 1616 + 720
= 2336 cm
(b)
Total length of B and C = 3 u + 720 + 1 u + 240
= 3 u + 1 u + 720 + 240
= 4 x 808 + 960 = 3232 + 960 = 4192 cm Answer(s): (a) 2336 cm; (b) 4192 cm