Question

a drop of oil of volume 000000000•1m spreads out on water to make a circular film of radius 0•1m what is the thickness of the film?

Answer 1

the oil forms a cylinder on the water. So, with thickness h,

πr^2 h = v
So plug in your numbers. I can't make out what you mean by placing the decimal point where you did in the volume value ... (and anyway, v is in m^3, not m)