If a first order reaction is completed to the extent of 75% and 50% in time interval, t1 and t2, what is the ratio t1:t2?
The half life of a radio active substance is 20 days. If 23 part of the substance has decayed in time t2 and 13 part of it has decayed in time t1 then the time interval between t2 and t1is(t2−t1)=