In the following question, by using which mathematical operators will the expression become correct?
30 ? 6 ? 4 ? 5 ? 4

Which two numbers should be interchanged to make the following equation correct?
7 – 8 ÷ 4 + 5 × 3 = 8 × 3 + 6 ÷ 2 – 3

The ratio of the present ages of Veeru and Sunita is 14:17 respectively. After 6 years from now the ratio of their ages will be 17:20 then, what is the present age of Veeru -

Reena is twice as old as Sunita. Three years ago, she was three time as old as Sunita. How old is Reena now?

If 6 * 9 – 4 = 58 and 3 * 9 – 7 = 34, then in the expression A * 4 – 9 = 91, what is the value of 'A'?

If A, represent ‘ – ‘ and C, represent ‘ × ‘, D represent ‘÷’, and E represent ‘+’ then the value of
14 C 3 A 12 E 4 D 2=?

Which two signs should be interchanged to make two given equation correct.
4 × 8 ÷ 16 – 4 + 6 – 3 + 2 = 32

If -4$1 = 4, 7$-7 = 49 and 3$1 = -3, then find the value of -8$-5 = ?