probability
posted by Anna on .
A survey of 850 students conducted in two schools showed the following results:
School A:
*Students who took the bus = 400
* Students who did not take the bus = 150
Total = 550
School B:
*Students who took the bus = 200
* Students who did not take the bus = 100
Total = 300
School C:
*Students who took the bus = 600
* Students who did not take the bus = 250
Total = 850
Calculate the probability that a randomly chosen student from this group of 850 students takes the bus and is from school A.

How bout "from this group of 550+300+850=1700 students"??
Assumeing that you meant 1700 students, there are 400 from School A that took the bus. Ergo, P=400/1700 = 23.5%