CAT Questions

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Choose 1 person for the single room & from the remaining choose 2 for the double room & from the remaining choose 4 people for the four person room, 

 Then, ⁷C₁ x ⁶C₂ x ⁴C₄ 

_{= 7 x 15 x 1 = 105}

By mistake = x/10 

Actual value = x * 10 

% Change = 10x-x1010x×100 = 99100×100  = 99% (negative)

Since actual value is greater than the wrong value.

Let the milk he bought is 1000 ml

Let C.P of 1000 ml is Rs. 100

Here let he is mixing K ml of water

He is getting 30% profit

=> Now, the selling price is also Rs. 100 for 1000 ml

=> 100 : K%

= 100 : 30

10 : 3 is ratio of milk to water

=> Percentage of milk = 10 x 100/13 = 1000/13 = 76.92%

Two men, three women and one child can be selected in ⁴C₂ x ⁶C₃ x ⁵C₁ ways = 600 ways.

A Mirage is a naturally occurring optical phenomenon in which light rays bend to produce a displaced image of distant objects or the sky.

• It is caused due to Total internal Reflection.

• It is an optical illusion observed in deserts or hot summer days due to which a person sees a pond of water some distance ahead of him in which the surrounding objects appear inverted.

How Mirage Forms::

1. The temperature of other layers of atmosphere goes on decreasing as we go up.
2. Therefore density and refractive index of air changes as one goes up.
3. Thus a ray of light,gets refracted more and more away from the normal.
4. At a particular angle when a ray of light exceeds critical angle, total internal reflection takes place and ray of light gets reflected in the same medium.
5. when the reflected ray reaches our eye, it appears as coming from tree or sky .
6. Hence the inverted image of tree creates an impression from a pond of water.

The first Indian woman to ever win an Olympic medal was Karnam Malleswari who won a bronze medal at the Sydney Olympics in the Women's 69 kg category in Weightlifting.

Let the sum be Rs. p, rate be R% p.a. and time be T years.

Then,

 P×T×(R+2)100-P×T×R100=108 ⇒2PT= 10800 ...... (1)

 And, 

 P×R×(T+2)100-P×R×T100=180 ⇒2PR = 18000 ......(2)

Clearly, from (1) and (2), we cannot find the value of p
So, the data is not sufficient.

2172+1832

= 200+172+200-172

It is in the form of a+b2+a-b2=2a2+b2

= 2(40000 + 289) = 80578.