A piece of ribbon 4900 cm long is cut into 3 parts, C, A and B.
C is 2 times as long as A.
B is 260 cm shorter than A.
Give the answers in cm.
- How much longer is C than A?
- What is the total length of C and B?
(a)
Choose the shortest length to be 1 u.
Length of B = 1 u
Length of A = 1 u + 260
Length of C = 2 x (1 u + 260) = 2 u + 520
Total length of C, A and B
= 2 u + 520 + 1 u + 260 + 1 u
= 2 u + 1 u + 1 u + 520 + 260
= 4 u + 780
4 u + 780 = 4900
4 u = 4900 - 780
4 u = 4120
1 u = 4120 ÷ 4 = 1030
Length of C longer than A
= 2 u + 520 - (1 u + 260)
= 2 u - 1 u + 520 - 260
= 1 u + 260
= 1 x 1030 + 260
= 1030 + 260
= 1290 cm
(b)
Total length of C and B
= 2 u + 520 + 1 u
= 3 u + 520
= 3 x 1030 + 520
= 3090 + 520
= 3610 cm
Answer(s): (a) 1290 cm; (b) 3610 cm