Question

How many four digit numbers are there which when divided by 11 leaves remainder 4.​

Answer 1

Last 4 digit number which is divisible by 11 is 9999. So next number is which will leave remainder 4 after dividing is 9999+4 = 10003(but it is 5 digit number) then to get a 4 digit number which will leave remainder 4 is 10003-11 = 9992.

So last digit is 9992
a= 1005
d= 11
Put this in formula
A(n) = a+(n-1)d
9992 = 1005 +(n-1)11
9992-1005 =(n-1)11
8987=(n-1)11
Dividing 8987 by 11 =(n-1)
817 = n-1
817+1 =n
n = 818