Quiz Discussion

If the sums of n terms of two arithmetic progressions are in the ratio $\frac{{3n + 5}}{{5n + 7}}$   then their nth terms are in the ration

• 1]

  $\frac{{3n - 1}}{{5n - 1}}$

• 2]

  $\frac{{3n + 1}}{{5n + 1}}$

• 3]

  $\frac{{5n + 1}}{{3n + 1}}$

• 4]

  $\frac{{5n - 1}}{{3n - 1}}$

(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 sum of the first four terms of an A.P. is 56. The sum of the last four terms is 112. If its first term is 11, the number of terms is

• 1]

  10

• 2]

  11

• 3]

  12

• 4]

  13

If three numbers be in G.P., then their logarithms will be in

• 1]

  AP

• 2]

  GP

• 3]

  HP

• 4]

   None Of This

What is the sum of the first 12 terms of an arithmetic progression if the 3^rd term is -13 and the 6^th term is -4?

• 1]

  -30

• 2]

  41

• 3]

  -23

• 4]

  -34