Quiz Discussion

(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 number of terms of the A.P. 3, 7, 11, 15, ....... to be taken so that the sum is 406 is

• 1]

  5

• 2]

  10

• 3]

  12

• 4]

  14

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

• 1]

  56

• 2]

  62

• 3]

  65

• 4]

  69

If the sum of n terms of an A.P. be 3n2 + n and its common difference is 6, then its first term is

• 1] 2
• 2] 3
• 3] 1
• 4] 4

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

• 1] -22
• 2] -25
• 3] -19
• 4] -28

A boy agrees to work at the rate of one rupee on the first day, two rupees on the second day, and four rupees on third day and so on. How much will the boy get if he started working on the 1st of February and finishes on the 20th of February?

• 1] 220
• 2] 220 -1
• 3] 219 -1
• 4] 219
• 5] None of these

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]

  204

What is the sum of the following series? -64, -66, -68, ......, -100

• 1] -1458
• 2] -1558
• 3] -1568
• 4] -1664

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

A bacteria gives birth to two new bacteria in each second and the life span of each bacteria is 5 seconds. The process of the reproduction is continuous until the death of the bacteria. initially there is one newly born bacteria at time t = 0, the find the total number of live bacteria just after 10 seconds :

• 1]

  \(\frac{{{3^{10}}}}{2}\)

• 2]

  310 - 210

• 3]

  243 × (35 -1)

• 4]

  310 - 25

• 5]

  None of these