Find the standard deviation of the following data (rounded off to two decimal places). 

5, 3, 4, 7 

The printed price of a TV set is ₹14,500. It is sold for ₹10,000 with two consecutive discounts. If the first discount is 10%, then what is the second discount?

Two boats are traveling with speeds of 36 km/hr and 54 km/hr respectively towards each other. What is the distance (in meters) between the two boats one second before they collide?

Each question below is followed by two statements A and B. You have to determine whether the data given in the statement is sufficient for answering the question. You should use the data and your knowledge of Mathematics to choose the best possible answer.
Give answer (A) if the statement A alone is sufficient to answer the question, but statement B alone is not sufficient.
Give answer (B) if the statement B alone is sufficient to answer the question, but statement A alone is not sufficient.
Give answer (C) if both statements A and B together are needed to answer the question.
Give answer (D) if either the statements A alone or statement B alone is sufficient to answer the question
Give answer (E) if you cannot get the answer from the statements A and B together, but need even more data.

What is the salary of P, in a group of P, Q, R, S, T and U, whose average salary is Rs. 35,000?
A. Total of the salary of Q and S is Rs. 54000.
B. Total of the salary of T and U is Rs. 58000.

$$ {5^{1\over 4}×(125)^{0.25}}$$ is equal to

The angle of elevation of the top of two vertical towers as seen from the middle point of the line joining the foot of the towers are 60° and 30°, respectively. The ratio of the heights of the tower is

Four coins whose diameter is 12.6 cm are placed in such a way that one coin touches the other coin, find the area between them.