Question

a piece of wire is of length 12 3/4 m. if it is cut into two piece in auch a way that the length of one piece 5 1/4 m. what is the length of other piece.

Answer 1

first convert from mixed fraction
12 3/4 =51/4

5 1/4 = 21/4

51/4 - 21/4 = 30/4 = 15/2

the length of other piece is 15/2 m

Answer 2

Total length of the rope is 77 . 
Let 'A' and 'B' be the two pieces into which the rope is cut.
Let 'x' be the length of rope 'A' 
Therefore length of rope 'B' = 4/7(X)

Total length of rope 
= A+b 
=77 
A+B =77
x + (4/7)×x =77
11/7×x =77
x=49 meters ( length of rope A)
Length of rope B = 4/7(49)
 B=28meters.
We know that A is the largest piece
So 3/4th of rope A 
= 3/4(49)
=36.75meters .