A piece of ribbon 4000 cm long is cut into 3 parts, A, B and C.
A is 2 times as long as B.
C is 260 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 + 260
Length of A = 2 x (1 u + 260) = 2 u + 520
Total length of A, B and C
= 2 u + 520 + 1 u + 260 + 1 u
= 2 u + 1 u + 1 u + 520 + 260
= 4 u + 780
4 u + 780 = 4000
4 u = 4000 - 780
4 u = 3220
1 u = 3220 ÷ 4 = 805
Length of C shorter than A
= 2 u + 520 - 1 u
= 2 u - 1 u + 520
= 1 u + 520
= 1 x 805 + 520
= 805 + 520
= 1325 cm
(b)
Total length of A and B = 2 u + 520 + 1 u + 260
= 2 u + 1 u + 520 + 260
= 3 x 805 + 780 = 2415 + 780 = 3195 cm Answer(s): (a) 1325 cm; (b) 3195 cm