Which of the following relations is correct for 

The mid points of AB and AC of a triangle ABC are respectively X & Y. If BC + XY = 12 units, then the value of BC - XY is:

∆ABC is an isosceles triangle with AB = AC = 15 cm and altitude from A on BC is 12 cm. Length of side BC is

If P = 3+1/p, the value of p⁴+1/p⁴ is :

If x-1/3x = 1/3 the value of 3x (x-1/3x) is

A and B start running at the same time and from the same point around a circle. If A can complete one round in 40 seconds and B in50 seconds, how many seconds will they take to reach the starting point simultaneously