Simplify: 3(10x + 7) – 15 =

Which of these numbers of simulations of an event would be most likely to produce results that are closest to those predicted by probability theory? 15, 20, 5, 10

See attachment below and find the equivalent of tan(∠qsr)

Bob the builder is making 480kg of cement mix. this is made by cement, sand and gravel in the ratio 1: 3: 4