Which is the odd number-pair?

Which is the next term in the following sequence of letter clusters?
PLaN, OJbP, NHcR, MFdT, LDeV,

The position of the first and the sixth digit in the number ‘9865474362’ are interchanged, similarly the positions of the second and the seventh digits are interchanged and so on. Which of the following will be the FOURTH digit from the left end after the rearrangement? 

In the class of boys and girls, the rank of Obama is15th and the rank of Shabana is 8th.The rank of Obama is 8th only in boys and Shabana’s rank is 4th only in girls. In the boys and girls, Obama’s rank is 18th from other side. Shabana’s rank is 7th only in girls from other end. Then find the total number of boys in the class. 

One day Faheema left school and walked 12 km towards North then she turned towards right and walked 7 km and then she turned towards left and walked 12 km. Again she turned towards right and walked 1 km. How much distance would she has to walk to reach her school straight? 

If 9th of the month falls on the day preceding Sunday, on what day will 1st of the month fall? 

Assertion (A): James Watt invented the steam engine.
Reason (R): It was invented to pump out the water from the flooded mines.

Find the missing number?
2, 12, 30, ?, 90, 132