Quiz Discussion

Find the nth term of the following sequence :

• 1]

  5(10n - 1)

• 2]

  5n(10n - 1)

• 3]

  \(\frac{5}{9} \times \left( {{{10}^n} - 1} \right)\)

• 4]

  \({\left( {\frac{5}{9}} \right)^n} \times \left( {{{10}^n} - 1} \right)\)

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

• 1]

  3

• 2]

  4

• 3]

  1

• 4]

  2

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)

The 2^nd and 6^th term of an arithmetic progression are 8 and 20 respectively. What is the 20^th term?

• 1]

  56

• 2]

  62

• 3]

  65

• 4]

  69

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

• 1]

  -2

• 2]

  -3

• 3]

  2

• 4]

  3

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

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

Find the 15th term of the sequence 20, 15, 10 . . . . .

• 1] -45
• 2] -55
• 3] -50
• 4] 0

15th term of A.P., x - 7, x - 2, x + 3, ........ is

• 1] x + 63
• 2] x + 73
• 3] x + 83
• 4] x + 53

A bacteria gives birth to two new bacteria in each second and the life span of each bacteria is 5 seconds. The process of the reproduction is continuous until the death of the bacteria. initially there is one newly born bacteria at time t = 0, the find the total number of live bacteria just after 10 seconds :

• 1]

  \(\frac{{{3^{10}}}}{2}\)

• 2]

  310 - 210

• 3]

  243 × (35 -1)

• 4]

  310 - 25

• 5]

  None of these