Question

1. If repetitions are not allowed, the number of
numbers consisting of 4 digits and divisible by
5 and formed out of 0, 1, 2, 3, 4, 5, 6 is
1) 220
2) 240
3) 370
4) 588​

Answer 1

Answer:

Number ending with either 0 or 5 is divisible by 5

Case 1) unit place is 0

Numbers=6×5×4=120

Case 2) unit digit is 5

Numbers =5×5×4=100

∴ total number =120+100=220

Answer 2

Answer:

220

Step-by-step explanation:

→ For divisibility by 5, unit's place should be 0 or 5

with 0, ----0

        6 choices ⇒  

6

C  

3

​  

×3!

                          =  

3!3!

6!

​  

×3!=6.5.4

                                                =120

with 5, ----5

        6 choices =120

                           

5

C  

2

​  

×2!=10×2=20

                           ⇒120+120−20=220

                                                 →(A)