Quiz Discussion

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

What is the sum of the first 13 terms of an arithmetic progression if the first term is -10 and last term is 26?

• 1] 104
• 2] 140
• 3] 84
• 4] 98

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]

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

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

The first and last term of an A.P. is a and l respectively. If S is the sum of all the terms of the A.P. and the common difference is given by $\frac{{{l^2} - {a^2}}}{{k - \left( {l + a} \right)}}$   then k = ?

• 1] S
• 2] 2S
• 3] 3S
• 4] None of these