<PRE><B>Question 504392</B>
Total expending for all students including 8 students did not join= Rs. 480 
Let
Total number students=x
Initial contribution for  one student was = 480/x

After 8 did not join  total students = x-8
Contribution for one student after 8 did not join = 480/x-8


Difference of contribution for one student = Contribution for one student after 8 did not join - Initial contribution for  one student
10= (480/x-8) – (480/x)
Taking LCM on right hand side
10=480x-480(x-8) / x(x-8)
10=480x-480x+3840 / x(x-8)
10 x(x-8)=3840
Divide by 10 both sides of the equation
x(x-8)=384
x^2-8x-384=0
x^2-24x+16x-384=0
x(x-24)+16(x-24)=0
(x+16)(x-24)=0
x+16=0 or x-24=0
x=-16 (impossible) or x=24

Total number students=24
Initial contribution for  one student was = 480/24= Rs. 20

After 8 did not join  total students = x-8 = 24-8=16
Contribution for one student = 480/16= Rs. 30

So 16 Students join the excursion.
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