Mathematics Tes...

If the equations x² – kx – 21 = 0 and x² – 3kx + 35 = 0 have a common root, then the value of k is

A box contains 15 balls. Of these balls, five each are of a different colour and the rest are all white. Five balls are drawn at random from the box. What is the probability that four balls are coloured and one is white?

The coefficient of the middle term in the expansion of (1 + x)²ⁿ is:

If$(p+q{)}^{th}$term of a G.P. be m and$(p-q{)}^{th}$term be n, then the$p^{th}$term will be

Seven people are sitting in a theater watching a show. The row they are in contains seven seats. After intermission, they return to the same row but choose seats randomly. What is the probability that neither of the people sitting in the two aisle seats was previously sitting in an aisle seat?

The value of X satisfying: 8x^3/2 - 8x^-3/2 = 63 is:

Find the sum of the series

(√3 + 1)⁴ + (√3 – 1)⁴ is

The coefficient of the middle term in the expansion of (1 + x)²ⁿ is:

A person forgot the last three digits of a telephone number, but remembered that these three were different digits. He dialed the last three digits at random. What is the probability that he has dialed the correct telephone number?