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

Some equations have been solved on the basis of a particular system. On the same basis, find the correct answer to the equation.
1 × 3 × 5= 531
2 × 7 ×9 =972
4 × 6 × 8=?

6 years ago, Raju's age was 2 years less than half of his brother's age, which was 20 years. What is his present age?

If 16 Δ 4= 64 and 216 @ 8=27 and what is the value of 8 Δ 5@ 4 =?

If ‘P’ means ‘÷’ and ‘Q’ means ‘+’ and ‘R’ means ‘×’ then Find the value of 16 P 8 Q 9 R 12?

If you write down all the numbers from 1 to 99, then how many times do you write 3?

If '+' becomes '-' and '×' becomes '÷', find the value of ((175 + 160) × 50) × 10.

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