Question

represesent decimal number 8620 in excess 3 code

Answer 1

to represent a decimal number in ex-3 code first of all we need to consider individual/separate numbers of the whole decimal number...we consider 8 6 2 and 0 separately...then add 3 individually i.e 8+3,6+3,2+3 and 0+3 we get 11, 9, 5 and 3 respectively....and now convert all these individual numbers to binary as 11 is 1101, 9 is 1001, 5 is 0101 and 3 is 0011 now join them and you will get the excess 3 code....i.e 1011100101010011.
thus (8620)10=(1011100101010011)ex-3...
hope its correct and you have understood....:-)