A piece of ribbon 1500 cm long is cut into 3 parts, C, A and B.
C is 4 times as long as A.
B is 180 cm shorter than A.
Give the answers in cm.
- How much longer is C than A?
- What is the total length of C and B?
(a)
Choose the shortest length to be 1 u.
Length of B = 1 u
Length of A = 1 u + 180
Length of C = 4 x (1 u + 180) = 4 u + 720
Total length of C, A and B
= 4 u + 720 + 1 u + 180 + 1 u
= 4 u + 1 u + 1 u + 720 + 180
= 6 u + 900
6 u + 900 = 1500
6 u = 1500 - 900
6 u = 600
1 u = 600 ÷ 6 = 100
Length of C longer than A
= 4 u + 720 - (1 u + 180)
= 4 u - 1 u + 720 - 180
= 3 u + 540
= 3 x 100 + 540
= 300 + 540
= 840 cm
(b)
Total length of C and B
= 4 u + 720 + 1 u
= 5 u + 720
= 5 x 100 + 720
= 500 + 720
= 1220 cm
Answer(s): (a) 840 cm; (b) 1220 cm