A piece of ribbon 4000 cm long is cut into 3 parts, A, B and C.
A is 3 times as long as B.
C is 230 cm shorter than B.
Give the answers in cm.
- How much shorter is C than A?
- What is the total length of A and B?
(a)
Choose the shortest length to be 1 u.
Length of C = 1 u
Length of B = 1 u + 230
Length of A = 3 x (1 u + 230) = 3 u + 690
Total length of A, B and C
= 3 u + 690 + 1 u + 230 + 1 u
= 3 u + 1 u + 1 u + 690 + 230
= 5 u + 920
5 u + 920 = 4000
5 u = 4000 - 920
5 u = 3080
1 u = 3080 ÷ 5 = 616
Length of C shorter than A
= 3 u + 690 - 1 u
= 3 u - 1 u + 690
= 2 u + 690
= 2 x 616 + 690
= 1232 + 690
= 1922 cm
(b)
Total length of A and B = 3 u + 690 + 1 u + 230
= 3 u + 1 u + 690 + 230
= 4 x 616 + 920 = 2464 + 920 = 3384 cm Answer(s): (a) 1922 cm; (b) 3384 cm