A cooking instructor stated that 5 pounds of roast beef is needed to serve 8 people. Based on the instructor's statement, which of the following equations can be used to find r, the number of pounds of roast beef needed to serve 12 people?

What is the simplified expression for 6(2(y+x))

At the beginning of 1974/75,2 years a man invested #2000 in a bank at 12.5% compound interest, if it degree #650 at the end of each two years to pay his son's school fees, after payment of interest to pay his son's school fees, how much did he have left at the beginning of the 1978/79 school year?

Find the solution of each of the following.