Find the missing number - 

8	16	8
5	15	10
9	36	?

Insert the correct mathematical signs in the following equation —

$13 3 2 1 = 15$

If

13 $\times$ 75 = 5731

27 $\times$ 34 = 4372

15 $\times$42 = 2451

then 16 $\times$ 36 = ?

If $15 \times 71 = 48$

$92 \times 23 = 55$

$37 \times 44 = 80$

then $54 \times 32 = ?$

If $+$ means $\times$, $-$ means $+$ and $\times$ means $÷$ find the value of $5+4-18\times 3.$

If $P$ denotes $÷$, $Q$ denotes $\times$, $R$ denotes $+$ and $S$ denotes $-$, then —

$18 Q 12 P 4 R 5 S 6 =$ ?