A piece of ribbon 3400 cm long is cut into 3 parts, B, A and C.
B is 2 times as long as A.
C is 140 cm shorter than A.
Give the answers in cm.
- How much shorter is C than B?
- What is the total length of B and A?
(a)
Choose the shortest length to be 1 u.
Length of C = 1 u
Length of A = 1 u + 140
Length of B = 2 x (1 u + 140) = 2 u + 280
Total length of B, A and C
= 2 u + 280 + 1 u + 140 + 1 u
= 2 u + 1 u + 1 u + 280 + 140
= 4 u + 420
4 u + 420 = 3400
4 u = 3400 - 420
4 u = 2980
1 u = 2980 ÷ 4 = 745
Length of C shorter than B
= 2 u + 280 - 1 u
= 2 u - 1 u + 280
= 1 u + 280
= 1 x 745 + 280
= 745 + 280
= 1025 cm
(b)
Total length of B and A = 2 u + 280 + 1 u + 140
= 2 u + 1 u + 280 + 140
= 3 x 745 + 420 = 2235 + 420 = 2655 cm Answer(s): (a) 1025 cm; (b) 2655 cm