Puzzle

A varies jointly with B and C. A = 6 when B = 3 and C = 2. Find A when B = 5 and C = 7.

In an examination a student had to find 3/14 of a number, he found 3/4th by mistake, his answer was 150 more than the correct answer, find the required number.

A man engaged a servant on the condition that he would pay him 90 and a turban after service of one year. He served only for nine months and received the turban and an amount of 65. The price of turban is 

The average temperature of Monday, Tuesday, Wednesday and Thursday is 60°. The average temperature for Tuesday, Wednesday, Thursday and Friday is 63°. If the ratio of temperature for Monday and Friday is 21 : 25, then what is the temperature of Friday ? 

Study the information carefully to answer the question that follow.

In a college there are 900 students who are doing Post Graduation (PG) in any one of the subjects, out of five different subjects, out of the five different subjects viz. Zoology, Botany, Mathematics, Physics and Statistics. The ratio between the boys and the girls among those is 5:4 respectively, 20% of the total girls are doing PG in Zoology and 25% of the total girls are doing PG in Statistics. Total number of students doing PG in Botany is 220. Total students who are doing PG in Mathematics is 150. Respectively ratio between the number of girls and the number of boys doing PG in statistics is 2:3. Twenty percent of the total number of boys are doing PG in Mathematics is 1:2 respectively. There are equal number of boys and girls who are doing PG in PG in Physics. 180 students are doing PG in Zoology.
Number of girls doing PG in Statistics is what percent of the number of boys doing PG in Physics?