CAT Questions

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A mixture is the blending of two or more dissimilar substances.

Characteristics of a Mixture:

1. It has No formula.

2. It is an impure sustance

3. They can be mixed in any ratio.

4. The properties of the mixture are the properties of its constituents.

5. Constituents can e easily seperated by physical methods.
eg: Heating, Drying, Crystallization, Distillation etc...

6. It is either homogenous or heterogenous.

A major characteristic of mixtures is that the materials do not chemically combine. Mixtures can be divided into those that are evenly distributed (homogeneous) and those that aren't (heterogeneous).

The gas usually filled in the electric bulb is Nitrogen.

American startup Planet Labs, that launches small satellites into orbit and sells the imagery, has announced its acquisition of Google's 'Terra Bella' satellite business. As part of the agreement, 60 Google employees will join the startup founded by ex-NASA scientists. Terra Bella, was acquired by Google in 2014 for $500 million and that time it was known as Skybox Imaging.

Indian business magnate Mukesh Ambani topples Jack Ma as Asia’s richest person as he positions Reliance Industries to disrupt the e-commerce space in India.

The chairman of India’s refining-to-telecoms conglomerate, Ambani was estimated to be worth US$44.3 billion in July 2018 with the share price of Reliance Industries rising 1.6 per cent to a record 1,099.8 rupees (US$16.05), according to Bloomberg Billionaires Index.

Jack Ma’s wealth stood at US$44 billion at the close of trading on the sameday in the US, where the company is listed.

Hubs are specified or operate at Layer1 i.e, the physical layer in the OSI model. Hubs regenerate electrical signals. A hub sends data packets (frames) to all devices on a network, regardless of any MAC addresses contained in the data packet.

We know that zero can't be in hundreds place. But let's assume that our number could start with zero.

The formula to find sum of all numbers in a permutation is

111 x no of ways numbers can be formed for a number at given position x sum of all given digits

No of 1 s depends on number of digits

So,the answer us

111 x 20 x (0+1+2+3+4+5) = 33300

We got 20 as follows. If we have 0 in units place we can form a number in 4*5 ways. This is for all numbers. So we have substituted 20 in formula.

Now, this is not the final answer because we have included 0 in hundreds place. so we have to remove the sum of all numbers that starts with 0.

This is nothing but the sum of all 2 digits numbers formed by 1 2 3 4 5. Because 0 at first place makes it a 2 digit number.

So the sum for this is 11 x 4 x (1+2+3+4+5).
=660

Hope u understood why we use 4. Each number can be formed in 4x1 ways

So, the final answer is 33300-660 = 32640

A number of possible explanations for why manhole covers are round include :

1. A round manhole cover cannot fall through its circular opening, whereas a square, rectangular, or oval manhole cover could fall in if it were inserted diagonally in the hole.

2. Circular covers don’t need to be rotated or precisely aligned when placing them on the opening.

3. A round manhole cover is easily moved and rolled.

4. Human beings have a roughly circular cross-section.

5. Round tubes are the strongest shape against the compression of the earth around them, so the cover of the tube would naturally be round as well.

6. It’s easier to dig a circular hole.