G is the centroid of ΔABC. The medians AD and BE intersect at right angles. If the lengths of AD and BE are 9 cm and 12 cm respectively; then the length of AB (in cm) is?

Three science classes A, B and C take a Science test. The average score of class A is 83. The average score of class B is 76. The average score of class C is 85. The average score of class A and B is 79 and average score of class B and C is 81. Then the average score of classes A, B and C is

The linear equation such that each point on its graph has an ordinate four times its abscissa is: 

It takes 53 seconds to cross a pole at the end of a 110-meter-long train with a speed of 36 km / h. Find the initial distance of the pole from its front end.

What decimal of a week is an hour? 

A shopkeeper allows 25% discount on his advertised price and to make a profit 25% on his outlay. What is the advertised price (in Rs.) on which he gains Rs. 6000?

A person lends 40 % of his sum of money at 15 % per annum, 50 % of rest at 10 % per annum and the rest at 18 % per annum rate of interest. What would be the annual rate of interest, if the interest is calculated on the whole sum? 

(0.04)^-1.5 on simplification gives: