Question

a clock hanging on wall breaks into 2 pieces sum of small is 31 and the sum of big piece is 30, how it breaks

Answer 1

Not sure what kind of “wall clock” you envision but, on a standard clock (with numerals 1 thru 12), the sum of the digits is 51, not 61.

Even if some of the digits were broken split into two digits (e.g.slicing the five ones, slicing a 1 from the 7, and maybe even slicing off another 1 from the 4) there is no way for the total of the digits on the two pieces to add up to 61.

However, the numbers (not the digits) on the clock add up to 78, so it’s possible that some of the digits are broken beyond recognition. If so, then there are several ways to eliminate unwanted digits and leave two pieces.