Questions

A : B = (800 × 8+ 900+ 1000+ 1100+ 1200): (1600 × 8+ 1700+ 1800+ 1900+ 2000)
A : B = 53 : 101
Profit of A ⇒ 7700 ×53/154 = 2650 Rs.

Magma is injected into surrounding rock forming an igneous intrusive.

Actually it is a plutonic formation in which magma present beneath Earth surface deforms the shape of rocks present above it
 

Molecular compounds are those with covalent bonds between the elements and those elements are typically non metals.

Here in the given options, Ar is an element. NaI has an ionic bond. Hence, N2O4 has a covalent bond between the two non metals and is a molecular compound.

The kidneys are stimulated to produce renin by a decrease in the blood pressure.

The renin-angiotensin system or RAS regulates blood pressure and fluid balance in the body. When blood volume or sodium levels in the body are low, or blood potassium is high, cells in the kidney release the enzyme, renin. Renin's primary function is therefore to eventually cause an increase in blood pressure, leading to restoration of perfusion pressure in the kidneys.

Sport played on horseback is called as Polo. It is the national sport of Iran.

Pages are denoted as 

1 - 9 = 09

10 - 99 = 90*2 = 180

100 = 03

Hence, total number of digits = 09 + 180 + 03 = 192.

Cretinism is a disease caused by hypothyroidism(less thyroxine formation).The symptoms of the disease are retardation  of mental, physical and sexual developments. Potbellt, protruding tongue, dry skin etc are also indicative of this disease.

Project Management is the application of Knowledge, skills, tools and techniques to project activities to meet project requirements. Project Management is accomplished through the application and integraton of the project management processes of  initiating, planning, executing, monitoring and controlling , closing.