Quiz Discussion

If the sum of three consecutive terms of an increasing A.P. is 51 and the product of the first and third of these terms is 273, then the third term is :

• 1] 13
• 2] 9
• 3] 21
• 4] 17

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

• 1]

  3

• 2]

  4

• 3]

  1

• 4]

  2

If k, 2k – 1 and 2k + 1 are three consecutive terms of an AP, the value of k is

• 1] -2
• 2] 3
• 3] -3
• 4] 6

The 3rd and 6th term of an arithmetic progression are 13 and -5 respectively. What is the 11th term?

• 1] -29
• 2] -41
• 3] -47
• 4] -35

Find the n^th term of the following sequence :
5 + 55 + 555 + . . . . T_n

• 1]

   

  5(10ⁿ - 1) 

• 2]

   

  5ⁿ(10ⁿ - 1)

• 3]

  5/9×(10ⁿ−1)

     

• 4]

  (5/9)ⁿ×(10ⁿ−1)

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)

If sum of n terms of an A.P. is 3n² + 5n and T^m = 164 then m =

• 1]

  26

• 2]

  27

• 3]

  28

• 4]

  None Of This

For an A.P. if a25 - a20 = 45, then d equals to:

• 1] 9
• 2] -9
• 3] 18
• 4] 23

In an A.P., if d = -4, n = 7, an = 4, then a is

• 1] 6
• 2] 7
• 3] 20
• 4] 28

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