There are only blue sweets, green sweets and red sweets in a box. the ratio of the number of blue sweets to the number of green sweets is 2: 7. the ratio of the number of green sweets to the number of red sweets is 3: 1. there are less than 140 sweets in the box. what is the greatest possible number of red sweets in the box?

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.