A piece of ribbon 2800 cm long is cut into 3 parts, C, B and A.
C is 3 times as long as B.
A is 250 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 + 250
Length of C = 3 x (1 u + 250) = 3 u + 750
Total length of C, B and A
= 3 u + 750 + 1 u + 250 + 1 u
= 3 u + 1 u + 1 u + 750 + 250
= 5 u + 1000
5 u + 1000 = 2800
5 u = 2800 - 1000
5 u = 1800
1 u = 1800 ÷ 5 = 360
Length of C longer than B
= 3 u + 750 - (1 u + 250)
= 3 u - 1 u + 750 - 250
= 2 u + 500
= 2 x 360 + 500
= 720 + 500
= 1220 cm
(b)
Total length of C and A
= 3 u + 750 + 1 u
= 4 u + 750
= 4 x 360 + 750
= 1440 + 750
= 2190 cm
Answer(s): (a) 1220 cm; (b) 2190 cm