The two lines of regression are 4x + 2y - 3 = 0 and 3x + 6y + 5 = 0. Find the correlation co-efficient between x and y.
A card is drawn from a well shuffled pack of playing cards. What is the probability that it is either a space or an ace or both ?
Solve the differential equation:
Let x + y = v
1 +
=