Help me please this is a test ASAP 30 points ???

Iknow its nothing to do with education, but what type of thing should i wrote here? ? : ) its for mcdonald's btw.

Jessie and bob are financing $425,500 to purchase a house. they obtained a 30/8 balloon mortgage at 6.55%. what will their balloon payment be?

The half-life of a certain material is 0.004 second. approximately how much of a 20-gram sample will be left after 0.016 second? a. 5 grams b. 16 grams c. 0.32 gram d. 1.25 grams