How many term of the A.P. 15 , 12, 9 ., - are needed to give the sum 15 ? Explain the duble answer .

How many terms of the A.P. 1,4,7.... are needed to give the sum 715?

How many terms of the AP -15, -13, -11, … are needed to make the sum -55 ?

How many terms of the AP -15, -13, -11, … are needed to make the sum -55 ?

How many terms of the A.P. -6, -(11)/2,\ -5,... are needed to give the sum -25?

How many terms of the A.P., -6,(-11)/(2),-5 ... are needed to give the sum-25 ?

How many terms of the A.P. 6 , -(11)/2 ,-5,dotdotdot are needed to give the sum 25 ?

How many terms of G.P. 3,3^2,3^3,dotdotdot are needed to give the sum 120?

How many terms of the A.P. 54, 51, 48, ... has the sum 513 ? Explain the double answer.

How many terms of the A.P. 24,20, 16, ... must be taken so that the sum may be 72? Explain the double answer.

How many terms of the A.P.: 9,17,25,..... must be taken to give a sum of 636?