rahul699

 Profile Answers by rahul699 

• Mar 21st, 2006

 

saurabh jyot singhnow first examine 7^1=77^2=497^3=3437^4=24017^5=16807hence after every 4 consecutive powers the unit's place follows the same patternhence to find 7^625 .. we can divide 625 by 4 ... which gives remainder 1 .. this has the same unit's place digit as 7^1if we had 7^626 .. then 626/4=2 ... hence unit's place digit = 9