A piece of ribbon 3300 cm long is cut into 3 parts, B, A and C.
B is 5 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 = 5 x (1 u + 130) = 5 u + 650
Total length of B, A and C
= 5 u + 650 + 1 u + 130 + 1 u
= 5 u + 1 u + 1 u + 650 + 130
= 7 u + 780
7 u + 780 = 3300
7 u = 3300 - 780
7 u = 2520
1 u = 2520 ÷ 7 = 360
Length of C shorter than B
= 5 u + 650 - 1 u
= 5 u - 1 u + 650
= 4 u + 650
= 4 x 360 + 650
= 1440 + 650
= 2090 cm
(b)
Total length of B and A = 5 u + 650 + 1 u + 130
= 5 u + 1 u + 650 + 130
= 6 x 360 + 780 = 2160 + 780 = 2940 cm Answer(s): (a) 2090 cm; (b) 2940 cm