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

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]

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

What is the sum of the first 12 terms of an arithmetic progression if the first term is -19 and last term is 36?

• 1] 192
• 2] 230
• 3] 102
• 4] 214

If 7 times the seventh term of an Arithmetic Progression (AP) is equal to 11 times its eleventh term, then the 18th term of the AP will be

• 1] 0
• 2] 1
• 3] 2
• 4] -1

If 18, a, b - 3 are in A.P. then a + b =

• 1] 19
• 2] 7
• 3] 11
• 4] 15

The sum of first n odd natural numbers in

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

If the fifth term of a GP is 81 and first term is 16, what will be the 4th term of the GP?

• 1] 36
• 2] 18
• 3] 54
• 4] 24
• 5] 27

How many terms are there in 20, 25, 30 . . . . . . 140?

• 1] 22
• 2] 25
• 3] 23
• 4] 24

Find the first term of an AP whose 8th and 12th terms are respectively 39 and 59.

• 1] 5
• 2] 6
• 3] 4
• 4] 3
• 5] 7

If the nth term of an A.P. is 2n + 1, then the sum of first n terms of the A.P. is

• 1] n(n - 2)
• 2] n(n + 2)
• 3] n(n + 1)
• 4] n(n - 1)