The equation of the tangent at the vertex of the parabola x2 + 4x + 2y = 0, is
x = - 2
x = 2
y = - 2
y = 2
The ratio in which yz-plane divides the line joining (2, 4, 5) and (3, 5, 7) is
- 2 : 3
2 : 3
3 : 2
- 3 : 2
A man 2 m tall walks at a uniform speed of 5 km/h away from a lamp post 6 m high. The rate at which the length of his shadow increases, is
2.5km/h
5km/h
15km/h
Seven weddings occur in a week. What is the probability that they happen on the same day?
None of these
Two small squares on a chess board are chosen at random. Probability that they have a common side is
D.
Two squares can be chosen in a single row by 7 ways as there are 8 squares in each row. But there are 8 rows. So, number of waysto
choose two squares in any of the row = 7 x 8 = 56. Similarly, number of ways to choose two squares in any of the column = 56