Quiz Discussion

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

• 1] 6
• 2] 7
• 3] 20
• 4] 28

If log 2, log (2^x -1) and log (2^x + 3) are in A.P, then x is equal to ___

• 1]

   

  5/2

• 2]

  log₂5

• 3]

  log₃2

• 4]

   

  3/2

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 7 times the seventh term of an Arithmetic Progression (AP) is equal to 11 times its eleventh term, then the 18th term of the AP will be

• 1] 0
• 2] 1
• 3] 2
• 4] -1

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