If ‘÷’ means ‘+’; ‘ –‘ means ‘x’; ‘x’ means ‘÷’ and ‘+’ means ‘ –‘; then 111 – 21 ÷ 7 × 2 + 4 – 127=?

Which two signs need to be interchanged to make the following equation correct?
45 – 9 ÷ 3 +5 ×6 =32

A father is 5 times as old as his son. His son is 6 years old. His son is 6 years old. After how many years, will the father be 4 times as old as his son?

In the following question, two signs and two numbers need to be interchanged to make it correct. Select the appropriate signs and number from the given alternatives.
6 × 8 + 2 = 20

If ‘+’ denotes ‘ –‘  and ‘ – ‘ denotes ‘×’  and ‘×’  denotes ‘÷’ and ‘÷’ denotes ‘+’ then what will be the numeric value of 60 × 10 ÷ 40 + 6 – 5 

If two is subtracted from each odd digit and three is added to each even digit in the number 3675249 how many digits will appear twice in the new number thus formed?