What decimal represents each number ?

The numbers on the left side of the point represent whole numbers such as ones, tens, hundreds, and thousands. The numbers on the right side of the point are the decimal values. Those numbers represent values called tenths, hundredths, thousandths, and so on.

I look this up but hope it helps!

Answer d; a supplementary angle = 180°, so if that angle = 150°, y would = 30°.