Three metal rods of length 77 cm, 110 cm and 121 cm are to be cut into parts of equal length. Each part must be as long as possible. What us the maximum number of pieces that can be cut?

28

The length of the equal parts cut from the three rods = HCF of 77, 110, 121

 77 = 7 x 11

110 = 2 x 5 x 11

121 = 11 x 11

⇒ HCF = 11

Now, if each rod is cut into pieces of length 11 cm,

Total number of such pieces = (sum of all other factors) 7 + 10 + 11 = 28