The no.  of  ways in  which  a  committee  of 5  members  can be  selected  from 6  men and 5 women consisting  of  3  men and  2 women is

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) -T_n =  21 ,  then the   value  of n is

In  how many  ways can  21 English  and  Hindi  books  be  placed  in a row,  so  that not two Hindi  books  are  together?

How many  no. of   6  digits  can be formed  from the  digits  of the number  112233?

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

How many  no. of five  digits   can be  formed from the  digits  2, 0, 4,3, 8  if   repetition of the  numbers  is not allowed.

How many  three -letter  words can  be   formed   from the  alphabets a, b, c, d  and  e,  if  repetition  is not allowed?

Seven  athletes  are  participating  in  a race.  In how  many ways the first three  prizes  can  be won?

If  ⁿC_r, denotes the no. of  combinations   of n  things  taken  r  at a  time,  then  the value of  expression

ⁿC_(r+1) +^rC_(r-1)+ 2ⁿC_r  is

Among   the 36 teachers in a school,  one principal  and one  vice principal are to be appointed.  In how  many  ways  this can be done?