Quiz Discussion

Consider an infinite G.P. with first term a and common ratio r, its sum is 4 and the second term is 3/4, then

• 1]

  a = 7/4, r = 3/7

• 2]

  a = 2, r = 3/8

• 3]

  a = 3, r = 1/4

• 4]

  a = 3/2, r = ½

Let S denotes the sum of n terms of an A.P. whose first term is a. If the common difference d is given by d = S_n – k S_n-1 + S_n-2 then k =

• 1]

  1

• 2]

  2

• 3]

  3

• 4]

  4

If the sum of n terms of an A.P. is 3n2 + 5n then which of its terms is 164 ?

• 1] 26th
• 2] 27th
• 3] 28th
• 4] None of these

What is the sum of all 3 digit numbers that leave a remainder of '2' when divided by 3?

• 1]

  897

• 2]

  1,64,850

• 3]

  1,64,749

• 4]

  1,49,700

The sum of n terms of an A.P. is 3n2 + 5n, then 164 is its

• 1] 24th term
• 2] 27th term
• 3] 26th term
• 4] 25th term

What is the sum of the first 17 terms of an arithmetic progression if the first term is -20 and last term is 28?

• 1] 68
• 2] 156
• 3] 142
• 4] 242

Find the 15th term of the sequence 20, 15, 10 . . . . .

• 1] -45
• 2] -55
• 3] -50
• 4] 0

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

• 1] 28
• 2] 87
• 3] 51
• 4] 17

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]

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