CAT Questions

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A person or scientist who studies on water is called as Hydrologist. Since the study of water and its properties is known as Hydrology, the persons who deals with this field are known as Hydrologists.

Geographer :

A scientist who studies Earth's natural environment and how human society uses the natural environment.

Herpetologist :

A person who studies reptiles and amphibians.

Archeologist :

Someone who studies people and what they did in the past from the things they left behind.

An English word with five letters in which if you remove the last four letters, still pronounced the same is QUEUE.

Length of largest tile = H.C.F. of 1517 cm and 902 cm = 41 cm.
Area of each tile = (41 x 41) sq.cm

Required number of tiles =1517 x 902/(41 x 41) = 814.

We are having with digits 2, 3, 4, 5 & 6 and numbers greater than 4000 are to be formed, no digit is repeated.

The number can be 4 digited but greater than 4000 or 5 digited.

Number of 4 digited numbers greater than 4000 are
4 or 5 or 6 can occupy thousand place => 3 x P34 = 3 x 24 = 72. 

5 digited numbers = P55 = 5! = 120 

So the total numbers greater than 4000 = 72 + 120 = 192

Let us say x boys and x girls joined the group.

(64 + x)/(40 + x) = 4/3

192 + 3x = 160 + 4x => x = 32

Number of members in the group = 64 + x + 40 + x

= 104 + 2x = 168.

The moderate temperatures allow Earth to maintain bodies of water into its normal state.

Changes in the bodies of water in terms of volume and structure would change due to the change in temperature. 

P( selecting atleast one couple) = 1 - P(selecting none of the couples for the prize) 

 = 1-16C1× 14C1×12C1×10C116C4=1539

A periscope is an optical instrument that uses a system of prisms, lenses, or mirrors to reflect images through a tube.

Light from a distant object strikes the top mirror and is then reflected at an angle of 90 degrees down the periscope tube. At the bottom of the periscope, the light strikes another mirror and is then reflected into the viewer’s eye.

Hence, A periscope works by the principle of Total internal reflection.