3i Infotech Placement Papers - 3i Infotech Interview Questions and Answers updated on 19.May.2024

The boy can select one trouser in nine ways.

The boy can select one shirt in 12 ways.

The number of ways in which he can select one trouser and one shirt is 9 * 12 = 108 ways.

n items of which p are alike of one kind, q alike of the other, r alike of another kind and the remaining are distinct can be arranged in a row in n!/p!q!r! ways.

The letter pattern 'MESMERISE' consists of 10 letters of which there are 2M's, 3E's, 2S's and 1I and 1R.

Number of arrangements = 9!/(2!)2 3!

Since we know that the interest rate is 0.15, and knowing that the difference between two years of compound interest is nothing but interest on interest, we can find the first year’s interest as –

45/0.15 = 300.

Now if the interest is 300 at the end of one year, then the principal is 300 / 0.15 = 2,000

To obtain Rs. 10, investment = Rs. 96.

To obtain Rs. 650, investment = Rs.96/10x 650 = Rs. 6240.

Getting 7 points is possible in 2 cases.

Case 1: India wins all 4 matches.

Probability: (.5)4 = .0625.

Case 2: India wins any of the 3 matches and draws the remaining match. This can happen in total 4 ways. Probability: 4 x (.50)3 x (.05) = .025.

So, required probability: .0625 + .025 = .0875

25 * 18/5 = 90 kmph

There are five letters in the given word.

Consider 5 blanks .

The first blank and last blank must be filled with N and A all the remaining three blanks can be filled with the remaining 3 letters in 3! ways.

The number of words = 3! = 6.

This can be solved using alligation.

What is required at the end of mixing is a price of 20/1.25 = 16.

So the alligation would look like this –

Water/0 Mixture/16 Chemical/25

Hence the ratio would be (25 – 16) : 16 = 9 : 16

Hence required ratio of Water : Chemical is 9:16.

As in denominator we have to take 1/3 four times so, we start by assuming 81 ml of dettol in the bottle. After the first iteration you will be left with

2/3 × 81 = 54 ml. After the second iteration you will be left with

2/3 × 54 = 36 ml. After the third iteration you will be left with

2/3 × 36 = 24 ml. After the fourth iteration you will be left with

2/3 × 24 = 16 ml. So the required ratio will be 16 : (81 – 16) = 16 : 65

Now the common difference of this AP is 16/4 = 4.

The sum of an AP is n/2 {2a + (n – 1)d}

Substituting we get, 40 = n/2 {2×-14 + (n – 1)4}

The best way to solve this is by plugging options. Put in n = 10 and get the RHS as 40.

The word MEADOWS has 7 letters of which 3 are vowels.

-V-V-V-

As the vowels have to occupy even places, they can be arranged in the 3 even places in 3! i.e., 6 ways. While the consonants can be arranged among themselves in the remaining 4 places in 4! i.e., 24 ways. 

Hence the total ways are 24 * 6 = 144.

We use formula for intersection of three sets, keeping in mind that Jan ∩ Mar does not exist, since they are not consecutive months.

Let x be the number of people defaulting in all 3 months.

We get the equation as : 125 = 50 + 60 + 40 – 20 – 10 + x. Solving we get x = 5.