The pharmacy has an old style balance scale
like the one above.
You have only two measuring counter weights:
• 30 grams
• 5 grams
Divide 300 grams of powder medicine
into 3 groups:
• one of 150 grams
• one of 100 grams
• one of 50 grams.
BUT... You can only weigh 3 times. Which means you can keep adding powder and manipulate the weights. But, when you take the powder off the scale, that's a final weight.
How would you do this and only use the scale for 3 measurements?