Some equations are solved on the basis of a certain system. Find the correct answer for the unsolved equation on that basis.
58 × 12 = 4, 37 × 96 = 5, 11 × 20 = 2, 42 × 12 = ? 

If - means ×, × mean000000s +, + means ÷ and ÷ means -, then
4 × 4 + 16 - 16 ÷ 30 = ?

If - stands for division, + for multiplication, ÷ for subtraction and × for addition, then which one of the following equations is correct? 

If - means ÷, + means ×, ÷ means -, × means +, then which of the following equations is correct? 

Some equations are solved on the basis of a certain system. Find the correct answer for the unsolved equation on that basis.
2 x 2 = 64, 3 x 1 = 27, 6 x 2 = 1728, 3 x 3 = ?

In a certain code language, ‘+’ represents ‘x’, ‘ – ‘ represent ‘+’, ‘x’ represent ‘÷’ and ‘÷’ represents ‘-‘. What  is the answer to the following question
15 – 5  + 25 ÷ 10 =?

If '+' means '÷', '–' means '+', '×' means '–' and '÷' means '×' then, 8 ÷ 4 - 6 + 3 × 4 =?  

Some equations are solved on the basis of a certain system. Identify that operation and find out the correct answer from the four-response given.
a = 14 (290) 15, b = 16 (330) 17, c = 18 (?) 19