If  ‘+’  means ‘÷’,   ‘ ̶ ’  means  ‘+’,   ‘×’ means  ‘ ̶ ’  and   ‘÷’  means  ‘×’,   what will be the value of the following expression?
 [{(38 × 23) - (4 ÷ 3)} + (6 - 3)] ÷ 2

If M denotes ‘−’, N denotes ‘÷’, O denotes ‘×’ and P denotes ‘+’, then what will come in place of ‘?’ in the following equation?
(38 O 13) N 19 M 27 P (38 O 3) P 43 M 68 = ?

After interchanging which two signs will the value of the given expression be ‘35’?

13 + 91 − 3 ÷ 529 × 23

Which two signs need to be interchanged to make the following equation correct?

73 – 13 × 42 ÷ 14 + 56 = 56

Direction: Some equations have been solved on the basis of certain system. Find the correct answer for the unsolved equation on that basis.

If 98 – 39 – 27 = 31, 87 – 38 – 34 = 20, then 79 – 25 – 12 = ?

By Interchanging the given two numbers which of the following equation will be not correct?
 3 and 8

By interchanging the given two signs, which of the following equations will NOT be correct?
 × and –
 I. 17 – 21 + 86 ÷ 2 × 13 = 387
 II. 10 + 63 – 12 × 259 ÷ 7 = 739

After interchanging the given two digits 4 and 6, what will be the value of the following equation?
 5 + 3 × 4 – 6 ÷ 2 = ?