A piece of ribbon 4400 cm long is cut into 3 parts, A, B and C.
A is 3 times as long as B.
C is 180 cm shorter than B.
Give the answers in cm.
- How much longer is A than B?
- What is the total length of A and C?
(a)
Choose the shortest length to be 1 u.
Length of C = 1 u
Length of B = 1 u + 180
Length of A = 3 x (1 u + 180) = 3 u + 540
Total length of A, B and C
= 3 u + 540 + 1 u + 180 + 1 u
= 3 u + 1 u + 1 u + 540 + 180
= 5 u + 720
5 u + 720 = 4400
5 u = 4400 - 720
5 u = 3680
1 u = 3680 ÷ 5 = 736
Length of A longer than B
= 3 u + 540 - (1 u + 180)
= 3 u - 1 u + 540 - 180
= 2 u + 360
= 2 x 736 + 360
= 1472 + 360
= 1832 cm
(b)
Total length of A and C
= 3 u + 540 + 1 u
= 4 u + 540
= 4 x 736 + 540
= 2944 + 540
= 3484 cm
Answer(s): (a) 1832 cm; (b) 3484 cm