A piece of ribbon 3800 cm long is cut into 3 parts, B, C and A.
B is 3 times as long as C.
A is 130 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 + 130
Length of B = 3 x (1 u + 130) = 3 u + 390
Total length of B, C and A
= 3 u + 390 + 1 u + 130 + 1 u
= 3 u + 1 u + 1 u + 390 + 130
= 5 u + 520
5 u + 520 = 3800
5 u = 3800 - 520
5 u = 3280
1 u = 3280 ÷ 5 = 656
Length of B longer than C
= 3 u + 390 - (1 u + 130)
= 3 u - 1 u + 390 - 130
= 2 u + 260
= 2 x 656 + 260
= 1312 + 260
= 1572 cm
(b)
Total length of B and A
= 3 u + 390 + 1 u
= 4 u + 390
= 4 x 656 + 390
= 2624 + 390
= 3014 cm
Answer(s): (a) 1572 cm; (b) 3014 cm