Find the increase or decrease percent when
a) 16 is increased to 20.
b) 20 is decreased to 16.
c) 40 is increased to 60.
d) 11 is increased to 44.

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