Expert: John Zalewski - 9/15/2011

Question
1.The reccommended dosage of Benadryl is 1.25 mg of Benadryl for every 2kg of body weight. How much should be given to a 37lb child?

2. The Grand Prix Formula 1 race this weekend is in Singapore. The race consists of 61 laps around a 5.067 km long track. At 225 miles per hour, how long will it take to go around once?

Answer
Hello, Michaelyn.


1. 1.25 mg/2 kg x 1 kg/2.2 lb x 37 lb


1.25 mg/2 kg (body weight) is given in the problem. Next, multiply this by 1 kg/2.2 lbs. There are 2.2 pounds in 1 kilogram. You put 'kg' on top in order to cancel out the 'kg' on the bottom in the first fraction.

When the 'kgs' cancel, you are left with mg/lbs. Finally, multiply this number by 37 to get the amount required for a 37-pound child.

1.25 mg/4.4 lbs x 37 lbs


= 46.25 (mg)(lbs)/4.4 (lbs)

= 10.5 mg

Answer: 10.5 mg

I'll let you try the second one by yourself. If you have questions, let me know.

Regards,
John