Quiz Discussion

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

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 9 terms of an arithmetic progression if the first term is 7 and last term is 55?

• 1] 219
• 2] 279
• 3] 231
• 4] 137

If the 7^th term of a H.P. is 1/10 and the 12^th term is 1/25, then the 20^th term is

• 1]

  1/41

• 2]

  1/45

• 3]

  1/49

• 4]

  1/37

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

(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 2nd and 6th term of an arithmetic progression are 8 and 20 respectively. What is the 20th term?

• 1] 56
• 2] 65
• 3] 59
• 4] 62

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]

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

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

• 1] 6
• 2] 7
• 3] 20
• 4] 28

The first term of an Arithmetic Progression is 22 and the last term is -11. If the sum is 66, the number of terms in the sequence are:

• 1] 10
• 2] 12
• 3] 9
• 4] 8