Quiz Discussion

The sum of the first 16 terms of an AP whose first term and third term are 5 and 15 respectively is

• 1] 600
• 2] 765
• 3] 640
• 4] 680
• 5] 690

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

• 1] 9
• 2] -9
• 3] 18
• 4] 23

If the first term of an A.P. is 2 and common difference is 4, then the sum of its 40 term is

• 1] 3200
• 2] 1600
• 3] 200
• 4] 2800

The 7th and 21st terms of an AP are 6 and -22 respectively. Find the 26th term

• 1] -34
• 2] -32
• 3] -12
• 4] -10
• 5] -16

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

Find the first term of an AP whose 8th and 12th terms are respectively 39 and 59.

• 1] 5
• 2] 6
• 3] 4
• 4] 3
• 5] 7

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

(1) + (1 + 1) + (1 + 1 + 1) + ....... + (1 + 1 + 1 + ...... n - 1 times) = ......

• 1]

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

• 2]

  \(\frac{{n\left( {n - 1} \right)}}{2}\)

• 3]

  \({n^2}\)

• 4]

  n

The common difference of the A.P. \(\frac{1}{3}, \frac{{1 - 3b}}{3} , \frac{{1 - 6b}}{3}\)   . . . . . . is

• 1]

  \(\frac{1}{3}\)

• 2]

  \( - \frac{1}{3}\)

• 3]

  -b

• 4]

  b