The half-life of radium is 1600 years. If 3 kg are present now, how much will be present after 16,000 years?

Two planes leave an airport at the same time, one flying east, the other flying west. the eastbound plane travels 20 mph slower. they are 1600 mi apart after 2 hr. find the speed of each plane.

Aculture started with 3000 bacteria. after 5 hours it grew to 3900 bacteria. predict how many bacteria will be present after 9 hours

Consider circle o, where and . m∠bpd °. °.