It takes ali 30 minute to mark a paper. aslam only needs 25 minutes to mark a paper. if they both start marking papers at 11;00 am at what time they will finish marking at the same time
The average height of 30 boys out of a class of 50, is 160 cm. If the average height of the remaining boys is 165 cm, the average height of the whole class (in cm) is: