1, the sum of the minuend, subtraction and difference is 120, so the sum of subtraction and difference is 120/2=60.

The difference is cubic subtraction, so the difference is 60/( 1+ 1/3)=45.

2. In the order11,1/2, 2/2, 1/3, 2/3, 3/3, 1/4, 2/4, 3/4.

There are 1 fractions with denominator of 1, 2 fractions with denominator of 2, 3 fractions with denominator of 3, 4 fractions with denominator of 4, and so on. And 5/ 12 is the fifth fraction whose denominator is 12.

So 5/ 12 is 1+2+3+4+ ... in rodents,+1+5 = 71.

3. Fill in the appropriate number on the horizontal line to minimize the remainder: -/28 = 946 ... (remainder)

The minimum remainder is 1.

So 28*946+ 1=26489.

The horizontal line is 26489.

4. There are four numbers 5, 13, 7, 3. Do four operations of "+,-,*,/"to make the result equal to 24. Your operation is: (13*5 +7)/3.