The length of a metallic rod is 7 m 3 cm long. Lynn cut the metallic rod into 3 pieces. The length of the first piece of the metallic rod is 55 cm. The length of the second piece of the metallic rod is 5 m shorter than the third piece. What is the length of the third piece of metallic rod?
1 m = 100 cm

Difference in the length between the second and the third piece
= 5 m
= 5 x 100
= 500 cm

Length of a metallic rod
= 7 m 3 cm
= 7 x 100 + 3
= 703 cm

Length of the first piece = 55 cm
Length of the second piece = 1 u
Length of the third piece = 1 u + 500 cm

1 u + 1 u + 500 + 55 = 703
2 u + 555 = 703
2 u = 703 - 555 = 148
1 u = 148 ÷ 2 = 74 

Length of the third piece of metallic rod
= 1 u + 500
= 74 + 500
= 574 cm

Answer(s): 574 cm