In the following series find the missing numbers.
21, 26, 33, 42, 53,?

Calendar of 1991 could be used again? 

Which one will replace the question mark?

In the following question, select the related number from the given alternatives.
328: 4:: 366: ?

In each of the following questions, four numbers are given out of which three are like in some manner while one is different. Choose the one which is different from the rest three?

In a certain code language, PINK is written as GREEN, GREEN is written as YELLOW, YELLOW is written as RED, RED is written as WHITE and WHITE is written as INDIGO, then in the same code language what is the colour of BLOOD?

If in a particular language, PAPER is coded as QZQDS and PENCIL is coded as QDOBJK then how is SCIENCE coded in that language?

Choose the correct option from the following options.
AZYB : CXWD ∷ BYWD :?