50% of all the cakes lucy bakes that week were party cakes: one fifth were fruit cakes and the remainder were sponge cakes. what percentage of cakes were sponge cakes ?

Element x decays radioactively with a half life of 8 minutes. if there are 450 grams of element x, how long, to the nearest tenth of a minute, would it take the element to decay to 37 grams?

What is the equation of a line that passes through points (0, 4) and (-4,-8)?

In the picture below, line pq is parallel to line rs, and the lines are cut by a transversal, line tu. the transversal is not perpendicular to the parallel lines. note: figure is not drawn to scale. which of the following are congruent angles?