Verbal Reasoning - Mental Ability Questions

If "α" denotes "subtracted from", "β" denotes "multiplied by", "θ" denotes "added to" and "δ" denotes "divided by", then 10 θ 8 β 4 δ 8 α 9 = ?

In the following question, select the missing number from the given series.
1, 3, 6, 10, 15, ?

From the given alternatives, select the word which CANNOT be formed using the letters of the given word.

Threatened

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

14 notebooks of a class were corrected with ink pen while 22 notebooks were corrected with colour pencil. If 4 notebooks were corrected with both, what is the strength of class?

A series is given with one term missing. Select the correct alternative from the given ones that will complete the series.
AY, CW, EU, ?

If 13 # 9 = 94 and 18 # 7 = 100, then 24 # 6 = ?

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

M_P_M_R_PM_PM_RR_P