The length of a wooden block is 4 m 5 cm long. Hazel cut the wooden block into 3 pieces. The length of the first piece of the wooden block is 71 cm. The length of the second piece of the wooden block is 1 m shorter than the third piece. What is the length of the third piece of wooden block?
1 m = 100 cm

Difference in the length between the second and the third piece
= 1 m
= 1 x 100
= 100 cm

Length of a wooden block
= 4 m 5 cm
= 4 x 100 + 5
= 405 cm

Length of the first piece = 71 cm
Length of the second piece = 1 u
Length of the third piece = 1 u + 100 cm

1 u + 1 u + 100 + 71 = 405
2 u + 171 = 405
2 u = 405 - 171 = 234
1 u = 234 ÷ 2 = 117 

Length of the third piece of wooden block
= 1 u + 100
= 117 + 100
= 217 cm

Answer(s): 217 cm