How many gallons of rocket fuel containing 80% liquid oxygen must be mixed with 250 gallons containing 40% liquid oxygen to produce a mixture containing 70% oxygen?

In triangle opq right angled at p op=7cm,oq-pq=1 determine the values of sinq and cosq

Find the center and the radius of the circle with the equation: x^2-2x+y^2+4y+1=0?

The moats separating people from the animals are 5 m wide for lions and 4 m wide for the elephants. if the lion’s moat is 4 m deep, how deep should the elephants’ moat be?