There is general formula for solution to such problems

If u have two things which costs same are sold one at x% profit and another at x% loss then theere will be aloss of x*x / 100 ( in percent ) on the transaction

x mile he drove in total
5 miles at 30/hr
x-5 at 60/hr

at 60 for whole trip he would take x/60 hrs
he actually takes 5/30 + x-5)/60

it greater by 1/6 -1/12= 1/12
as a percentage (1/12 )*100 /(x/60) =500/x

I thing D gets the meaning all wrong. It says that the penal sysyem be reformed as penitentiaries. The wrong things r compared here.
C gets it right by saying penitentiary system to be used as part of reform of penal system

Look at it this way B says there are 24 integers between X and Y So supposing it starts with an even integer then it will end with an odd one and if it starts with an odd one it will end with an even integer so there are always 12 odd and 12 even integers in abunch of 24 consecutive intyegers Modify...

The question should say Greatest Prime factor in S

ramesh u should say that the angle subtended at the center is 90 sinnce 1/4 *360=90 then go ahead to solve

The Q stem can be simplefied to say x-3 = 3-x ie 2x=6 or is x=3

1 is sufficient

2 says x is negative so cannot be equal to 3 hence sufficient

so ans is D