Let Tn denote the no. of triangles which can be formed using the vertices of a regular polygon of n sides. If T(n+1) -Tn = 21 , then the value of n is
5
7
6
4
If 2nP3= 2. nP4, then the values of n is
4,5
6,10
1,8
2,4
How many three -letter words can be formed from the alphabets a, b, c, d and e, if repetition is not allowed?
25
60
100
The no. of ways in which 6 men and 5 women can dine on a round table' if not two women are to sit together, is
30
5! x 5!
5! x 4!
7! x 5!
A polygon has 44 diagonals. The no. of its sides is
11
8
In how many ways 6 persons can stand in a queue at a time?
120
240
480
720
In a party , 12 persons are to be arranged in a round table. If two particular persons are not to sit side by side, then the total no. of arrangements is
9 x 10!
2 x 10!
45 x 8!
10!
The no. of 5 digit numbers that can be formed with the digits 0,1,2,3,4 if the numbers can be repeated in the same number is
250
2500
12500
The no. of diagonals of a polygon of n sides is
n (n-1)/2
n (n-2)/2
n(n-3)/2
n (n-5)/2
A father with 8 children take 3 at a time to a zoological garden. If the father without taking the same 3 children more than once, then the no. of times he will go to the garden is
336
112
56
28
