Quiz Discussion

Let S denotes the sum of n terms of an A.P. whose first term is a. If the common difference d is given by d = S_n – k S_n-1 + S_n-2 then k =

• 1]

  1

• 2]

  2

• 3]

  3

• 4]

  4

What is the sum of the first 12 terms of an arithmetic progression if the first term is -19 and last term is 36?

• 1] 192
• 2] 230
• 3] 102
• 4] 214

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

A piece of equipment cost a certain factory 6,00,000. If it depreciates in value, 15% the first year, 13.5% the next year, 12% the third year, and so on, what will be its value at the end of 10 years, all percentages applying to the original cost?

• 1] Rs. 2,00,000
• 2] Rs. 1,05,000
• 3] Rs. 4,05,000
• 4] Rs. 6,50,000

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)

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

• 1]

  6

• 2]

  7

• 3]

  20

• 4]

  28

What is the sum of the first 12 terms of an arithmetic progression if the first term is -19 and last term is 36?

• 1]

  192

• 2]

  230

• 3]

  102

• 4]

  204

If S1 is the sum of an arithmetic progression of ‘n’ odd number of terms and S2 is the sum of the terms of the series in odd places, then \(\frac{{{S_1}}}{{{S_2}}}\)

• 1]

  \(\frac{{2n}}{{n + 1}}\)

• 2]

  \(\frac{n}{{n + 1}}\)

• 3]

  \(\frac{{n + 1}}{{2n}}\)

• 4]

  \(\frac{{n - 1}}{n}\)

If the sum of p terms of an A.P. is q and the sum of q terms is p, then the sum of (p + q) terms will be

• 1] 0
• 2] p - q
• 3] p + q
• 4] -(p + q)

How many terms are there in 20, 25, 30 . . . . . . 140?

• 1] 22
• 2] 25
• 3] 23
• 4] 24