A piece of ribbon 3300 cm long is cut into 3 parts, C, A and B.
C is 2 times as long as A.
B is 120 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 + 120
Length of C = 2 x (1 u + 120) = 2 u + 240
Total length of C, A and B
= 2 u + 240 + 1 u + 120 + 1 u
= 2 u + 1 u + 1 u + 240 + 120
= 4 u + 360
4 u + 360 = 3300
4 u = 3300 - 360
4 u = 2940
1 u = 2940 ÷ 4 = 735
Length of C longer than A
= 2 u + 240 - (1 u + 120)
= 2 u - 1 u + 240 - 120
= 1 u + 120
= 1 x 735 + 120
= 735 + 120
= 855 cm
(b)
Total length of C and B
= 2 u + 240 + 1 u
= 3 u + 240
= 3 x 735 + 240
= 2205 + 240
= 2445 cm
Answer(s): (a) 855 cm; (b) 2445 cm