A piece of ribbon 1400 cm long is cut into 3 parts, B, A and C.
B is 3 times as long as A.
C is 130 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 + 130
Length of B = 3 x (1 u + 130) = 3 u + 390
Total length of B, A and C
= 3 u + 390 + 1 u + 130 + 1 u
= 3 u + 1 u + 1 u + 390 + 130
= 5 u + 520
5 u + 520 = 1400
5 u = 1400 - 520
5 u = 880
1 u = 880 ÷ 5 = 176
Length of C shorter than B
= 3 u + 390 - 1 u
= 3 u - 1 u + 390
= 2 u + 390
= 2 x 176 + 390
= 352 + 390
= 742 cm
(b)
Total length of B and A = 3 u + 390 + 1 u + 130
= 3 u + 1 u + 390 + 130
= 4 x 176 + 520 = 704 + 520 = 1224 cm Answer(s): (a) 742 cm; (b) 1224 cm