in a cycle race there are 5 persons named as j, k, l, m, n participated for 5 positions so that in how many number of ways can m make always before n?
Answers
Answer:
60
Step-by-step explanation:
In a cycle race there are 5 persons named as j, k, l, m, n participated for 5 positions so that in how many number of ways can m make always before n?
there are 5 persons
so total number of ways = 5!
= 5 * 4 * 3 * 2 * 1
= 120
out of 120 ways
Either m will be before n or after n
=> m before n = (1/2) * 120 = 60
in total 60 ways m can always make before n
other way to to solve
if m 1st then all can be at any place including n
= 4 * 3 * 2 * 1= 24
if m = 2 then n can be 3 , 4 or 5 & other 3 can be any of the remaining 3 position
= 3! * 3 = 18
if m = 3 then n can be 4 or 5 & other 3 can be any of the remaining 3 position
= 3! * 2 = 12
if m = 4 then n can be 5 & other 3 can be any of the remaining 3 position
= 3! * 1 = 6
m = 5th not possible
So total ways = 24 + 18 + 12 + 6 = 60