A bag contains 10 rupee coins, 7 fifty paise coins and 4 twenty- five paise coins. Find the probability of drawing
  (i)     a rupee coin
 (ii)     3  rupee coins
(iii)   3 coins, one of each type, in the random drawing of the three coins from the bag

[ Answer : (i) 55/133   ;     (ii)  12/133      (iii)   4/19   ]

NO LINKS PLEASE