Quiz Discussion

Sum of n terms of the series \(\sqrt 2   +   \sqrt 8   +   \sqrt {18}   +   \sqrt {32}   +  \) ....... is

• 1]

  \(\frac{{n\left( {n + 1} \right)}}{2}\)

• 2]

  \(2n\left( {n + 1} \right)\)

• 3]

  \(\frac{{n\left( {n + 1} \right)}}{{\sqrt 2 }}\)

• 4]

  1

If Sn denote the sum of the first n terms of an A.P. If S2n = 3Sn , then S3n : Sn is equal to

• 1] 4
• 2] 6
• 3] 8
• 4] 10

If a, b, c are in A.P., then (a – c)²/ (b² – ac) =

• 1]

  3

• 2]

  4

• 3]

  1

• 4]

  2

If a + 1, 2a + 1, 4a - 1 are in A.P., then the value of a is:

• 1]

  1

• 2]

  2

• 3]

  3

• 4]

  4

The nth term of an A.P., the sum of whose n terms is Sn, is

• 1] Sn + Sn - 1
• 2] Sn - Sn - 1
• 3] Sn + Sn + 1
• 4] Sn - Sn + 1

If the sum of the series 2 + 5 + 8 + 11 … is 60100, then the number of terms are

• 1]

  100

• 2]

  150

• 3]

  200

• 4]

  250

The first term of an Arithmetic Progression is 22 and the last term is -11. If the sum is 66, the number of terms in the sequence are:

• 1]

  9

• 2]

  10

• 3]

  11

• 4]

  12

If the fifth term of a GP is 81 and first term is 16, what will be the 4th term of the GP?

• 1] 36
• 2] 18
• 3] 54
• 4] 24
• 5] 27

The sum of the first and third term of an arithmetic progression is 12 and the product of first and second term is 24, then first term is

• 1]

  4

• 2]

  1

• 3]

  8

• 4]

  6

If the sum of p terms of an A.P. is q and the sum of q terms is p, then the sum of (p + q) terms will be

• 1] 0
• 2] p - q
• 3] p + q
• 4] -(p + q)