Me with these 3 problems ! 20 points

Estimate the product. round the first factor to the nearest whole number, round the second factor to the nearest ten, and then multiply. 3 8/9 × 96

What value of x is in the solution set of 4x - 12 s 16 + 8x? -10 -9 -8 -7

Two cars which are 40 miles apart start moving simultaneously in the same direction with constant speeds. if the speed of the car which is behind is 56 mph and the speed of the other car is 48 mph, how many hours will it take for the car which is behind to catch up the car ahead of it?