Questions

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.

Today, internet plays a pivotal role in both B2B and B2C space. Internet advertising helps the company to reach a large target audience in a small budget and also is easily measurable. It’s highly effective in creating and increasing brand awareness on a whole for any product/service.

The following are the various ways to measure the effectiveness of online advertising:

•      Downloading of brochures/contact forms


•      Completing a transaction on Shopping cart section of the website


•      Subscription to newsletter/webinars


•      Online enquiry about the product/service through company’s email address


•      Google analytics


•      Web analytics  

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.

No. of  sweets each student get = 20% of 65 = 13

No. of sweets each teacher get = 40% of 65 = 26

No. of sweets distributed to 65 students =  13 × 65 = 845

No. of sweets distributed to 4 teachers = 4 × 26 = 104

Therefore, the total no. of sweets there = 845 + 104 = 949.