A piece of ribbon 4200 cm long is cut into 3 parts, C, B and A.
C is 3 times as long as B.
A is 150 cm shorter than B.
Give the answers in cm.
- How much longer is C than B?
- What is the total length of C and A?
(a)
Choose the shortest length to be 1 u.
Length of A = 1 u
Length of B = 1 u + 150
Length of C = 3 x (1 u + 150) = 3 u + 450
Total length of C, B and A
= 3 u + 450 + 1 u + 150 + 1 u
= 3 u + 1 u + 1 u + 450 + 150
= 5 u + 600
5 u + 600 = 4200
5 u = 4200 - 600
5 u = 3600
1 u = 3600 ÷ 5 = 720
Length of C longer than B
= 3 u + 450 - (1 u + 150)
= 3 u - 1 u + 450 - 150
= 2 u + 300
= 2 x 720 + 300
= 1440 + 300
= 1740 cm
(b)
Total length of C and A
= 3 u + 450 + 1 u
= 4 u + 450
= 4 x 720 + 450
= 2880 + 450
= 3330 cm
Answer(s): (a) 1740 cm; (b) 3330 cm