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?
72 x 9 - 14 + 2 = ?

Which set of letters when sequentially placed at the gaps in the given letter series shall complete it?

x_zz_xx_z_yx

In the following question, which one set of letters when sequentially placed at the gaps in the given letter series shall complete it?

ab_ _abbc_aa_bbb

From the given words, select the word which cannot be formed using the letters of the given word. CIRCUMSTANCES

If 879= 8, 625= 1, 586= 9, then 785 = ?

Rearrange the jumbled letters to make a meaningful word and then select the one which is different.

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

?, flight lieutenant, squadron leader, wing commander

Which set of letters when sequentially placed at the gaps in the given letter series shall complete it?

j_l_jk_m_kl_