Two towns A and B are 60 KM apart. A school is to be built to serve 150 students in town B. If the total distance to be travelled by all 200 students is to be small as possible, then the school at

(a) town B

(b) 45 KM from town A

© town A

(d) 45 KM from town B

Choose some location between town A and town B. If we move one cm closer to town A then thats 150cm less that students from town A must travel, and 50 more cm that students from town B must travel. So,100 fewer total cm traveled by students for each cm closer to A you make it. Therefore, building it right on  town A will minimize the total distance all the students need to travel.