Write an expression that represents the sum of 7 and x

If the wwight of a package is multiplied by 7/10 the result is 65.8 find the weight of the package

The pyramid below was dissected by a horizontal plane which shape describes the pyramid horizontal cross section

The distribution of the amount of money spent by students for textbooks in a semester is approximately normal in shape with a mean of $235 and a standard deviation of $20. according to the standard deviation rule, how much did almost all (99.7%) of the students spend on textbooks in a semester?