Quiz Discussion

If the nth term of an A.P. is 2n + 1, then the sum of first n terms of the A.P. is

• 1] n(n - 2)
• 2] n(n + 2)
• 3] n(n + 1)
• 4] n(n - 1)

The 3rd and 9th term of an arithmetic progression are -8 and 10 respectively. What is the 16th term?

• 1] 34
• 2] 28
• 3] 25
• 4] 31

How many terms are there in the GP 5, 20, 80, 320........... 20480?

• 1] 5
• 2] 6
• 3] 8
• 4] 9
• 5] 7

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)

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

• 1] 9
• 2] -9
• 3] 18
• 4] 23

A boy agrees to work at the rate of one rupee on the first day, two rupees on the second day, and four rupees on third day and so on. How much will the boy get if he started working on the 1st of February and finishes on the 20th of February?

• 1] 220
• 2] 220 -1
• 3] 219 -1
• 4] 219
• 5] None of these

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 4th and 7th term of an arithmetic progression are 11 and -4 respectively. What is the 15th term?

• 1] -49
• 2] -44
• 3] -39
• 4] -34

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

• 1]

  6

• 2]

  7

• 3]

  20

• 4]

  28

The 3rd and 7th term of an arithmetic progression are -9 and 11 respectively. What is the 15th term?

• 1] 28
• 2] 87
• 3] 51
• 4] 17