If it is possible to make a meaningful word of English together with the first, fifth and eighth letters of the word APTITUDES, how many total words can be made of this type? 

Select the combination ofletters that when sequentially placed in the blanks of the given series will complete the series.
 dq_pln_qt_lnd_tpl_dq_p_n

Which one set of letters when sequentially placed at the gaps in the given letter series shall complete it.
deb, ijg, nol ? xyv

What will come in place of question mark(?) in the following number series?

BCF, CDG , DEH, ?

Select the option that represents the letters that, when placed from left to right in the following blanks, will complete the letter-series.
 Q W _ R T Q _ F R _ Q W _ _ T _ _ H R T

From the given alternatives the word which cannot be formed using the letters of the given word
PSYCHOLOGY

Directions : Study the following alphanumeric series carefully and answer the questions given below:

12AIFR                  42 WBOL                             63EOCN                15TVMR               75GYTR

The letters which are attached with the numbers in which at least one is odd digit are arranged according to the ascending orders of their numbers from left to right and then all letters of the words together are arranged in the alphabetical order, then which of the following is the 9^th letter from the right end?

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