Algebra & Manipulation · Superchallenge problem

Gear A has $36$ teeth and meshes with gear B, which has $24$ teeth. Gear B is fixed to the same axle as gear C, which has $30$ teeth, so B and C always turn together. Gear C meshes with gear D, which has $18$ teeth. When gear A makes $10$ full turns, how many full turns does gear D make?