1) The half life of Uranium 230 is 20.8 days, the time needed for 50% to decay. How long would it take for 20% of Uranium 230 to decay?
2) How long after 7:30 are a clock's minute hand and hour hand 50 degree apart?
3) A triangle has a fixed side dimension of length 7 in, and the opposite angle is also fixed and equal to 37 degree. What is the maximum triangle area?