Find a right triangle

Jenisey has $24 to spend on seven pencils. after buying them she had $10. how much did each pencil cost.?

Ammonia molecules have three hydrogen atoms and one nitrogen atom. how many of each atom arein five molecules of ammonia

Find the actual dimensions of the box. the side length are in meters and integers. the surface area of the box is 104 m2 and volume of the box is 60 m3.