Verbal Reasoning - Mental Ability Questions

In a certain code language, '+' represents 'x', '-' represents '+', 'x' represents '÷' and '÷' represents '-'. What is the answer to the following question?
550 x 22 - 24 + 3 = ?

If 10$25 = 8, 12$25 = 10 then what is the value of 14$53 = ?

A series is given, with one term missing. Choose the correct alternative from the given ones that will complete the series.

PMT, OOS, NQR, MSQ, ?

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

What should come in place of the question mark (?) in the following number series? 1, 3, 24, 360,8640, 302400, ?

Pointing towards a man Soumya says, "His mother's daughter is my sister". How is Soumya related to the man?

In the given series is written in the reverse order, then what will be the 5th term to the left of the 10th term from right end?

R+JM2$#QR?*O@7F3

In the following question, select the related letters from the given alternatives.
AEDM : ZQRN : : FLMO : ?