Quiz Discussion

If a, b, c are in A.P., then (a – c)²/ (b² – ac) =

• 1]

  3

• 2]

  4

• 3]

  1

• 4]

  2

The sum of first five multiples of 3 is:

• 1] 45
• 2] 65
• 3] 75
• 4] 90

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]

  \(\frac{{5n - 1}}{{3n - 1}}\)

The sum of first n odd natural numbers in

• 1] 2n - 1
• 2] 2n + 1
• 3] n2
• 4] n2 - 1

The 3rd and 8th term of an arithmetic progression are -13 and 2 respectively. What is the 14th term?

• 1] 23
• 2] 17
• 3] 20
• 4] 26

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

If k, 2k – 1 and 2k + 1 are three consecutive terms of an AP, the value of k is

• 1] -2
• 2] 3
• 3] -3
• 4] 6

(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

If four numbers in A.P. are such that their sum is 50 and the greatest number is 4 times the least, then the numbers are

• 1] 5, 10, 15, 20
• 2] 4, 10, 16, 22
• 3] 3, 7, 11, 15
• 4] None of these

The 3^rd and 7^th term of an arithmetic progression are -9 and 11 respectively. What is the 15^th term?

• 1]

  28

• 2]

  87

• 3]

  51

• 4]

  17