Question

What is the sum of all 4 digit number formed using the digits 2,3,4 and 5 without repitation?

Answer 1

for getting the sum of 4 digits numbers we can apply the formula as follows:-

(sum of given digits) * 1111...n (given number of digits) * (number of digits-1)!

eg:- to find the sum of 4 digits using 2 , 3 , 4 , 5

sol:- (2+3+4+5) * (1111) * ( 4-1 )! = (14 ) * ( 1111 ) * ( 3! ) = 14 * 1111 * 6 = 93324

Hope this helps ☺️☺️

Answer 2

✍︎......︎︎︎ᴥ︎︎︎︎︎︎ Aɴsᴡᴇʀ࿐

Total no. of digits are 5, i.e., n=5

Total no. of digits required is 4, i.e.,

r = 4

Therefore,

No. of 4 digits no. that can be formed =nPr=5P4=1!5!=120

No. of times each digit will appear =5120=24

Sum of digits at unit place =24(1+3+5+7+9)=24×25=600

Sum of all numbers =600×1000+600×100+600×10+600=666600

Hence the sum off all 4 diit numbers is 666600.

P.S: As 0 has no Value so I didn't mention it.

H O P E I T H E L P S !!!

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#PsʏᴄʜᴏHᴇʀᴇ

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