You have 5 pill bottles; 4 bottles contain 10 x 10mg pills, and 1 bottle has 10 x 9mg pills. You have digital scales and can only weigh 1 time. You label the the bottles 1, 2, 3, 4, 5. You may remove the pills from the bottle to weigh them. Find which bottle contains the 9mg pills. The weight from your one try is 147 mg.