Quiz Discussion

What is the sum of the first 11 terms of an arithmetic progression if the 3rd term is -1 and the 8th term is 19?

• 1] 204
• 2] 121
• 3] 225
• 4] 104

The 2^nd and 8^th term of an arithmetic progression are 17 and -1 respectively. What is the 14^th term?

• 1]

  -19

• 2]

  -22

• 3]

  -20

• 4]

  -25

The common difference of the A.P. \(\frac{1}{{2b}} \frac{{1 - 6b}}{{2b}}  \frac{{1 - 12b}}{{2b}}\)   . . . . . is

• 1] 2b
• 2] -2b
• 3] 3
• 4] -3

If 18, a, b - 3 are in A.P. then a + b =

• 1] 19
• 2] 7
• 3] 11
• 4] 15

The sum of first n odd natural numbers in

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

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

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

If the 7^th term of a H.P. is 1/10 and the 12^th term is 1/25, then the 20^th term is

• 1]

  1/41

• 2]

  1/45

• 3]

  1/49

• 4]

  1/37

Which term of the A.P. 92, 88, 84, 80, ...... is 0?

• 1]

  23

• 2]

  32

• 3]

  24

• 4]

  28

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