The expression in company B represents that is is in arithmetic progression where first term is 42000 and common difference is 1800 . So we have to use the formula of sum of n terms which is
Where a is the first term, n is the nth term, d is the common difference
On substituting there values,we will get
= 15(84000+52200) = 15*136200 =2043000
And for company A, it is
Difference between them =2043000-2002500= 40500
So the correct option is the second option .