In how many ways can six persons be paired?
...In how many ways can six persons be paired?
5
10
15
20
Correct answer is C
6C\(_2 = \frac{6!}{[6-2]![2!]}\)
\(\frac{6*5*4!}{4!*2!}\)
= \(\frac{6*5}{2}\)
= 15
Find the equation of the line passing through (0, -1) and parallel to the y- axis. ...
Find the range of values of x for which \(2x^{2} + 7x - 15 > 0\)....
Evaluate \(\int_{1}^{2} [\frac{x^{3} - 1}{x^{2}}] \mathrm {d} x\)...
The angle of a sector of a circle is 0.9 radians. If the radius of the circle is 4cm, find the ...
Find the coefficient of \(x^{3}\) in the binomial expansion of \((x - \frac{3}{x^{2}})^{9}\)....
If sin x = \(\frac{12}{13}\) and sin y = \(\frac{4}{5}\), where x and y are acute angles, find&...