Wesley makes spherical fish tanks with a diameter of 30 cm. A customer requests a smaller tank with half the volume of the tank that Wesley usually makes. What is the approximate diameter of the smaller tank?

Dylan and dusty plan to take weekly surfing lessons together. if the 2-hour lessons are $20 per person and they plan to spend $100 each on new surfboards, what is the maximum number of lessons the two can take if the total amount spent for lessons and surfboards is at most $480?

Astick 2 m long is placed vertically at point b. the top of the stick is in line with the top of a tree as seen from point a, which is 3 m from the stick and 30 m from the tree. how tall is the tree?

The volume of a sphere is increased by 6%. calculate the corresponding percentage increased in it area.