jim can do the 1/2 of floor in 4 hours
pete completes 1/2 of floor in 2 hour
therefor, since, pete took 1/2 as much time, pete can tile 2 times as many tiles (logic)
pete can lay 25 more than jim
if pete is 2 times of jim
p=2j
and pete is 25 more than jim
p=25+j
2j=p=25+j
2j=25+j
minus j
j=25
jim lays at 25 tiles per hour
C is answer
