Question

15) How many different numbers of six digits without repetition can be formed from the digits 0,1,,3,5,7,9?

How many of them will have 0 in the unit place?

How many of them are divisible by 5?

How many of them are not divisible by 5?

Answer 1

Total number of ways in which 6 letter can formed is 5×6×4×3×2×1

2) 5×4×3×2×1×1

3)fixing 5 on unit place we get no. of ways = 5×4×3×2×1

fixing 0 on unit place =5×4×3×2×1

total no. of ways i.e add both of them

4)total ways minus numbers divisible by 5

hope it will help you.