A piece of ribbon 5000 cm long is cut into 3 parts, A, B and C.
A is 3 times as long as B.
C is 130 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 + 130
Length of A = 3 x (1 u + 130) = 3 u + 390
Total length of A, B and C
= 3 u + 390 + 1 u + 130 + 1 u
= 3 u + 1 u + 1 u + 390 + 130
= 5 u + 520
5 u + 520 = 5000
5 u = 5000 - 520
5 u = 4480
1 u = 4480 ÷ 5 = 896
Length of C shorter than A
= 3 u + 390 - 1 u
= 3 u - 1 u + 390
= 2 u + 390
= 2 x 896 + 390
= 1792 + 390
= 2182 cm
(b)
Total length of A and B = 3 u + 390 + 1 u + 130
= 3 u + 1 u + 390 + 130
= 4 x 896 + 520 = 3584 + 520 = 4104 cm Answer(s): (a) 2182 cm; (b) 4104 cm
