Question

In a certain commercial bank customers may withdraw cash through either of the tellers at the counter. On average the teller takes 3 minutes while another teller takes 5 minutes to serve the customer at the same time. Find the shortest time it takes to serve 200 customers.

Answer 1

16 hours 

Answer 2

2 minutes

Answer 3

6hrs  15min

Answer 4

3000

Answer 5

Let the number of customers served by first teller be x and number of customer served by 2 nd teller 200-x
If for first teller 
1customer= 3 min 
x=?
3x min
If  for 2 nd teller 
1 customer= 5 min 
(200-x)=?
5(200-x)= 1000-5x
So 
3x= 1000-5x
8x= 1000
x= 125 customers 
Time taken 
125×3= 375 minutes = 6hours 15 minutes 

Answer 6

300