If 246*2 = 6, 870*3 = 11, then what should 735*5 be?

Select the correct combination of mathematical signs to replace * signs and to balance the equation.
2000 * 1300 * 20 * 20 * 300

If '+' means '÷' ;  ‘÷’means ' - ' ; ' - ' means '×' ; '×' means '+' , then
8 + 2÷ 3- 4 x 6 =? 

Which of the following signs of equation are to be interchanged which will make the given equation correct?

5 + 6 ÷ 3 – 12 × 2 = 17

If 21 (49) 14 and 159 (169) 146, then what is the value of 'A' in 56 (A) 44? 

Which two signs should be interchanged in the following equation to make it correct?
24 ÷ 8 – 5 x 5+ 3 = 13

If 1x 3 x 5 = 1925 and 7 x 9 x 11 = 4981121, then 19 x 21 x 28 is equal to?

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 = ?