Questions

In order to protect the operating systems and the system programs from the malfunctioning programs the two mode operations were evolved

System mode

User mode

Hospitality actually means, taking care of guests in the best possible way.

Organizing, providing services and looking care after guests is included in it.

It means friendly and generous treatment of guests. 

Hospitality industry includes all companies involved in providing services for guests. They provide more mental satisfaction than tangible objects.

Cellular respiration is best associated with the organelle Mitochondrion.

Delhi has highestnumber of historical monuments

In the given puzzle, the logic is

2 + 3 = 10 => (2 + 3) * 2 = 10

6 + 3 = 54 => (6 + 3) * 6 = 54

8 + 3 = 88 =>  (8 + 3) * 8 = 88

Similarly,

9 + 7  => (9 + 7) * 9 = 16 x 9 = 144.

Among the given options, mud is not an aerosol.

An aerosol is a suspension of fine solid particles or liquid droplets, in the air or another gas. Aerosols can be natural or anthropogenic. Examples of natural aerosols are fog, dust, forest exudates and geyser steam. Examples of anthropogenic aerosols are haze, particulate air pollutants, and smoke.