The total Number of students in a class is: 60
How to find the number of students?
Customers are asked to stand in the lines.
If one customer is extra in a line, then there would be two less lines.
If one customer is less in line, there would be three more lines.
Let's say that there are C customers in a Line and total of L number of lines. Thus:
Total number of customers = ( customers in a line) * (number of Lines)
Total number of customers = CL
If one customer is extra in a line, then there would be two less lines. Thus:
Total number of customers = (C + 1)(L -2) (C + 1)(L -2) = CL
=> CL + L - 2C - 2 = CL
=> L - 2C = 2 - eq 1
If one customer is less in line, there would be three more lines. Thus:
number of customers = (C - 1)(L +3) (C - 1)(L +3) = CL
=> CL - L + 3C - 3 = CL
=> - L + 3C = 3 - eq 2
Adding eq 1 & eq 2 => C = 5
L - 2(5) = 2 => L = 12
5 customers in a Line
Total Number of students = CL = 5*12 = 60
Complete question is:
Customers are asked to stand in the lines. If one customer is extra in a line, then there would be two less lines. If one customer is less in line, there would be three more lines. Find the number of students in the class.
a) 40
b) 50
c) 60
d) 70