Ten runners join a race. in how many possible ways can they be arranged as first, second, and third placer? pls answer

Ans: 720

This is equal to the number of different arrangements of three persons from a group of 10 persons 

Required number of ways = 10P3 = 720

OR can be solved in this way
select 3 runners (10C3 ways)
These 3 runners can be arranged in 3! ways
Total = 10C3×3! = 720

Ans: 720

This is equal to the number of different arrangements of three persons from a group of 10 persons 

Required number of ways = 10P3 = 720

OR can be solved in this way
select 3 runners (10C3 ways)
These 3 runners can be arranged in 3! ways
Total = 10C3×3! = 720 .hope i was able to help :)