A boat rows downstream covers a distance of 20 km in 2 hrs while it covers the same distance upstream in 5 hrs. Then speed of the boat in still water is : 

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.

Some persons can do a piece of work in 12 days. Two times the number of such persons will do half of the work in 

What is the highest common factor of 2x³ + x² -x -2 and 3x³- 2x² + x - 2 ? 

The simple interest on a certain sum of money at the rate of 5 % per annum for 8 years is ₹ 840. Rate of interest for which the same amount of interest can be received on the same sum after 5 years is? 

∆ ABC  is right angle at B. If m∠C = 45⁰ Then find the value of ( cosec A - √3) = ?

What least value which should be added to 1812 to make it divisible 7,11 and 14?