What is the most common material used for making

What will be the value of the given expression after the following interchanges?

Expression: 84 ÷ 11 - 15 X 14 + 75

Which of the following interchange of sign would make the given equation correct?

45 × 9 + 5 ÷ 4 = 25

Select the correct combination of mathematical signs that can sequentially replace '*' sign and balance the equation given below.

12* 6 * 3 * 54 * 9 * 12

If '÷' means '+', '+' mean '-', 'x' means '÷' and '-' means 'x', then what will be the value of the given expression:

12 – 6 x 2 + 5 ÷ 9

If '@' means '÷', '#' means ' X ', '$' means '+' and '%' means '-' then what would be the value of the expression given below?

If,

40 – 14 means 560,

168 + 8 means 21,

26 ÷ 2 means 28,

8 x 7 means 1,

then 410 – 7 x 290 ÷ 350 + 7 x 21 = ?

Which of the following “signs” are placed in place of “symbols” given in equation to make the equation true?

Which one of the given mathematical operations will result in 291?