A piece of ribbon 4600 cm long is cut into 3 parts, B, C and A.
B is 3 times as long as C.
A is 250 cm shorter than C.
Give the answers in cm.
- How much longer is B than C?
- What is the total length of B and A?
(a)
Choose the shortest length to be 1 u.
Length of A = 1 u
Length of C = 1 u + 250
Length of B = 3 x (1 u + 250) = 3 u + 750
Total length of B, C and A
= 3 u + 750 + 1 u + 250 + 1 u
= 3 u + 1 u + 1 u + 750 + 250
= 5 u + 1000
5 u + 1000 = 4600
5 u = 4600 - 1000
5 u = 3600
1 u = 3600 ÷ 5 = 720
Length of B longer than C
= 3 u + 750 - (1 u + 250)
= 3 u - 1 u + 750 - 250
= 2 u + 500
= 2 x 720 + 500
= 1440 + 500
= 1940 cm
(b)
Total length of B and A
= 3 u + 750 + 1 u
= 4 u + 750
= 4 x 720 + 750
= 2880 + 750
= 3630 cm
Answer(s): (a) 1940 cm; (b) 3630 cm