<prompt> What is the clearance of a substance, if its concentration in plasma is 10 mg, concentration in urine is 100 mg and urine flow is 2 mlmin?0.02 mlmin0.2 mlmin2 mlmin20 mlmin  <response>: Ans. D. 20mlmin.rate of elimination amount of drug excreted per hour concentration in urine x urine flow 2mgmin 100 mg x 2 mlminNow Cl RoEPlasma concentration Therefore, Clearance 2mgmin10mg20mlmin. 