Quiz Discussion

If Sn denote the sum of the first n terms of an A.P. If S2n = 3Sn , then S3n : Sn is equal to

• 1] 4
• 2] 6
• 3] 8
• 4] 10

If a + 1, 2a + 1, 4a - 1 are in A.P., then the value of a is:

• 1]

  1

• 2]

  2

• 3]

  3

• 4]

  4

A piece of equipment cost a certain factory 6,00,000. If it depreciates in value, 15% the first year, 13.5% the next year, 12% the third year, and so on, what will be its value at the end of 10 years, all percentages applying to the original cost?

• 1] Rs. 2,00,000
• 2] Rs. 1,05,000
• 3] Rs. 4,05,000
• 4] Rs. 6,50,000

The 2^nd and 8^th term of an arithmetic progression are 17 and -1 respectively. What is the 14^th term?

• 1]

  -19

• 2]

  -22

• 3]

  -20

• 4]

  -25

What is the sum of the first 11 terms of an arithmetic progression if the 3rd term is -1 and the 8th term is 19?

• 1] 204
• 2] 121
• 3] 225
• 4] 104

Two A.P.’s have the same common difference. The first term of one of these is 8 and that of the other is 3. The difference between their 30th terms is

• 1] 11
• 2] 3
• 3] 8
• 4] 5

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

• 1] -45
• 2] -55
• 3] -50
• 4] 0

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]

  9

• 2]

  10

• 3]

  11

• 4]

  12

For an A.P. if a25 - a20 = 45, then d equals to:

• 1] 9
• 2] -9
• 3] 18
• 4] 23

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