Two points P and Q are on longitude 67°W. Their latitudes differ by 90°. Calculate their distance apart in terms of π. (Take radius of the earth = 6400km).

Solve me equation: 2/3 (x + 5) = 1/4(5x - 3)

A and B are two sets. The number of elements in A∪B is 49, the number in A is 22 and number in B is 34. How many elements are in A ∩ E?

Simplify log39 + log315 - log35

A student found the approximate value of 0.02548 correct to two places of decimal instead of two significant figures. Find the percentage error.

Which of the following equations has its roots as 4 and -5?

If P = {3, 5, 6} and Q = {4, 5, 6} then P∩Q equals

Express (0.0425 / 2.5) as a fraction

Solve the equations: 4x -y = 11; 5x + 2y = 4.