what power of 15 divides 87! exactly?
a)20
b)29
c)30
d)14

• Option (a) will be the answer
  
  Reason- 15 = 5*3 we will get the pair of 5 and 3
  
  [87/5] + [87/5^2] = 17 + 5 = 20 ( we will get 20 fives)
  
  [87/3] + [87/3^2] + [87/3^3] + [87/3^4] = 29 + 9 + 3 + 1 = 42(we will get 42 threes)
  
  but we have only 20 fives that's why we will get only 20 pair of 5 & 3.
• 11 years agoHelpfull: Yes(2) No(2)
• option a will be the ans.
  find no of 3,5 in 87!.
  this will give you ans .
  :)
• 11 years agoHelpfull: Yes(0) No(2)