What approximate value should come in the place of question mark (?) in the following question?
 (8423 + 3120 + 6543) ÷ (1536 + 377 + 189) = ?

The value of $$ {3sin30°-4sin^{3}30°}$$

A 240 meter long train crosses a 300 meter long platform in 27 seconds. What is the speed of the train in Kmph?

If tan (11 θ)=cot (7θ), then what is the value of sin²(6 θ) + Sec² (9 θ) + cosec²(12 θ)?

Sumitra has an average of 56% on her first 7 examinations. How much should she make on her eighth examination to obtain an average of 60% on 8 examinations?

An article is sold at a loss of 40%. The nominal amount of loss is approximately what percentage of the selling price of the article?

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.
What is the respective ratio between the boys doing PG in Mathematics and the number of girls doing PG in Botany?

A square pyramid with side 10 cm has a volume of 400 cm³. Find the total surface area of the pyramid.