If tan y = 0.404, where y is acute, find cos 2y

A baker used 40% of a 50kg of flour. If $\tfrac{1}{8}$ of the amount used was for cake, how many kilogram of flour was used for the cake? 

If 30% of y is equal to x, what, in terms of x is 30% of 3y

A fair coin is tossed three times. Find the probability of getting two head and one tail 

P is a point on the same plane with a fixed point A. If P moves such that it is always equidistant from A, the locus of P is

Given that $\frac{1-2x}{4x-3}$, find the value of x for which y is undefined

Simplify $\frac{x-4}{4}-\frac{x-3}{6}$

Simplify $\frac{{{25}^{\tfrac{2}{3}}}\div {{25}^{\tfrac{1}{6}}}}{{{({1}/{5}\;)}^{-\tfrac{7}{6}}}\times {{({1}/{5}\;)}^{\tfrac{1}{6}}}}$

Simplify 11011_two – 1101_two

Evaluate (0.13)³ correct to three significant figures.