How many 4 digits number are formed by the numbers 0 to 9 which are less than 4000 and divisible by 5
Answers
Answer:
I'll try to explain this as easy as possible and that's the way my maths sir during my IIT coaching told us
(0–9) has 10 numbers
2. Think of 4digits as 4blocks, _ _ _ _
3. The first block can be occupied by 9 numbers (1–9) , why not 0 -> if you include zero , the number will become 3 digit
4. The second block will then be occupied by any of the remaining 9 numbers (0–9 excluding the number choosen in step 3)
5. The choices of choosing the numbers is decreasing as blocks are filling …this time for filling third block we have 8 numbers and for fourth block 7 numbers
Using the total choices of each block and multiplying them we get total 4 digit numbers
=> 9*9*8*7 ( read step 3 if you have doubt regarding the first 9 choices and not 10 )
=> 4536
Step-by-step explanation: this might help you and please mark me as the brainliest