Use PEMDAS with the first 3.
a. 3×(6÷5)
3×(1.2) [Parenthesis first]
3.6. [then multiply]
b. 3÷(5×6)
3÷(30) [Parenthesis first]
.1 [then divide]
c. (3×6)÷5
(18)÷5 [Parenthesis first]
3.6 [then divide]
d. 3×6÷5
18÷5 [Left to right]
