Quiz Discussion

The sum of first n odd natural numbers in

• 1] 2n - 1
• 2] 2n + 1
• 3] n2
• 4] n2 - 1

If an A.P. has a = 1, tn = 20 and sn = 399, then value of n is :

• 1] 20
• 2] 32
• 3] 38
• 4] 40

The sum of first five multiples of 3 is:

• 1]

  90

• 2]

  72

• 3]

  55

• 4]

  45

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 three numbers be in G.P., then their logarithms will be in

• 1]

  AP

• 2]

  GP

• 3]

  HP

• 4]

   None Of This

What is the sum of the first 9 terms of an arithmetic progression if the first term is 7 and last term is 55?

• 1] 219
• 2] 279
• 3] 231
• 4] 137

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 two geometric means between the number 1 and 64 are

• 1]

  8 and 16

• 2]

  2 and 16

• 3]

  4 and 8

• 4]

  4 and 16

If the 3rd and the 5th term of an arithmetic progression are 13 and 21, what is the 13th term?

• 1] 53
• 2] 49
• 3] 57
• 4] 61

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)