How many 10 digit numbers can be formed using the digits

In a certain code language, FEATHERS is written as BIQDBKPU. How will POSITION be written in that language?

Vacuum Tubes were used in which generation of Computers?

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

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

In the given arrangement, what is the sum of 8th number from the right end and 6th number from the left end?

In the given arrangement, how many numbers are between the second symbol from the right end and the third symbol from the left end?

Select the option that represents the letters that, when sequentially placed from left to right in the blanks below, will complete the letter series.

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

Four letter-clusters have been given, out of which three are alike in some manner and one is different. Select the letter-cluster that is different.