A piece of ribbon 1300 cm long is cut into 3 parts, A, B and C.
A is 5 times as long as B.
C is 170 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 + 170
Length of A = 5 x (1 u + 170) = 5 u + 850
Total length of A, B and C
= 5 u + 850 + 1 u + 170 + 1 u
= 5 u + 1 u + 1 u + 850 + 170
= 7 u + 1020
7 u + 1020 = 1300
7 u = 1300 - 1020
7 u = 280
1 u = 280 ÷ 7 = 40
Length of C shorter than A
= 5 u + 850 - 1 u
= 5 u - 1 u + 850
= 4 u + 850
= 4 x 40 + 850
= 160 + 850
= 1010 cm
(b)
Total length of A and B = 5 u + 850 + 1 u + 170
= 5 u + 1 u + 850 + 170
= 6 x 40 + 1020 = 240 + 1020 = 1260 cm Answer(s): (a) 1010 cm; (b) 1260 cm