Mary is 3 years older than her brother. her brother is half as old as their mom. the sum of all three of their age is 63. how old is mary?

An automated water dispenser fills packets with one liter of water on average, with a standard deviation of 5 milliliter. the manual says that after a year of operation the dispenser should be tested to see if it needs recalibration. a year later a number of filled packets are set aside and measured separately. it is found that the average packet now contains about 0.995 liters. does the dispenser need calibration? explain your answer.

The ratio of the measures of the three angles in a triangle is 2: 9: 4. find the measures of the angels

Give me the equations of two lines that have the same slope but are not parallel.