A piece of ribbon 3300 cm long is cut into 3 parts, A, B and C.
A is 3 times as long as B.
C is 220 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 + 220
Length of A = 3 x (1 u + 220) = 3 u + 660
Total length of A, B and C
= 3 u + 660 + 1 u + 220 + 1 u
= 3 u + 1 u + 1 u + 660 + 220
= 5 u + 880
5 u + 880 = 3300
5 u = 3300 - 880
5 u = 2420
1 u = 2420 ÷ 5 = 484
Length of C shorter than A
= 3 u + 660 - 1 u
= 3 u - 1 u + 660
= 2 u + 660
= 2 x 484 + 660
= 968 + 660
= 1628 cm
(b)
Total length of A and B = 3 u + 660 + 1 u + 220
= 3 u + 1 u + 660 + 220
= 4 x 484 + 880 = 1936 + 880 = 2816 cm Answer(s): (a) 1628 cm; (b) 2816 cm