Pls help me with these multi-choice question for my test tomorrow:
Ques.1.) If the first,second and last term of an A.P. are a, b and 2a respectively, its sum is :

ab ab 3ab
a) ------- b) ----- c) ------
2(b-a) b-a 2(b-a)

The book says the answer is c) but I just cant get it...pls help

Question

Pls help me with these multi-choice question for my test tomorrow:
Ques.1.) If the first,second and last term of an A.P. are a, b and 2a respectively, its sum is :

         ab                     ab              3ab
a)  -------           b) -----     c) ------
      2(b-a)                  b-a           2(b-a)

The book says the answer is c) but I just cant get it...pls help

anonymous · Answer

Ques.2.) If S1 is the sum of an A.P. of "n" odd number of terms and S2 the sum of the terms of the series in odd places, then S1/S2 =

      2n                  n              n+1               n+1
a) -----      b) -----    c) ------     d) -------
      n+1             n+1             2n                  n

The book gives a) as the answer.

How to solve these?????

anonymous · Answer

Friends, I finally solved the first one...!!!

Pls help with the second one......plllllssssss

anonymous · Answer

solved the second one too..........!!!!! woooooohoooooo!!!!

anonymous · Answer

Sorry, this is way out of my league :)

anonymous · Answer

Its ok.  Thanks for taking the trouble of looking into this...