Select the letter-cluster that can replace the question mark (?) in the following series.
FIY, HLD, JOI, LRN, NUS, ?

If 5th September 2008 was a Monday, what day of the week was 9th October 2008? 

What comes next in the series?
765, 642, 519, 396, 273 ?

Seismograph: Earthquakes: Taseometer : ? 

Select the letter that will come next in the following series.
O, R, U, X, A, ___

Select the letter-pair that can replace the question mark (?) in. the following series
BA, DC, FE, HG, ? , LK

If Q is the brother of K. S is sister of K, and T is the sister of S, so let's say K, what is the relation of T? 

If COOL is coded as DQRP, then write the code for HOT