Need help with this!!​

Find three consecutive numbers such that the sum of one-fourth the first and one-fifth the second is five less than one-seventh the third

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?

Look at triangle wxy what is the length (in centimeters) of the side wy of the triangle?