No of 1 Address 2 Address 0 Address Instructions Practice

Question

I have seen lots of questions like this :
A load-store architecture in which memory operation applied only on LOAD and STORE instructions and other all operations are REG-REG instructions. Assume three address architecture. Find the minimum number of instructions required to execute the expression $X =\frac{(A+B) - (C+D)}{E}$ in this load store architecture, where A, B, C, D, E and X are memory locations and expression evaluated on operands stored in these locations. Result stores in memory location X.

Some practice questions like these: 

1. $X=(A+B)*(C+D) $
   3AI: 3
   2AI:6
   1AI:7
   0AI:8
2. $X=A*B+C*C$
   3AI: 3
   2AI:6
   1AI:7
   0AI:8
3. $X=\frac{A-B}{C+D*E} $
   3AI: 4
   2AI:7
   1AI:8
   0AI:10
4.  $X=\frac{A-B+C*(D*E-F)}{G+H*K}$
   3AI: 8
   2AI:12
   1AI:16
   0AI:18
5.  $X=\frac{A+B*C}{D-E*F+G*H}$
   3AI: 7
   2AI:12
   1AI:15
   0AI:16
   
   Please comment if anything wrong!!!