Asked by  | 13th Feb, 2009, 10:23: PM

Expert Answer:

Assum that the first term of the A.P. is a and the common difference is d,

Then the nth term is given by the formula

nth term= a+(n-1)d

Acording to the question,

required expression =[a+(n-1)d]-[a+(k-1)d]=(n-k)d

when the 20th term is 10 more than the 18 th term,





Answered by  | 14th Feb, 2009, 08:54: AM

Queries asked on Sunday & after 7pm from Monday to Saturday will be answered after 12pm the next working day.