a group of friends goes for dinner and gets bill of Rs 2400
. Two of them says that they have forgotten their purse so
remaining make an extra contribution of Rs 100 to pay up
the bill. Tell the no. of person in that group
Let 'x' be the number of perons in the group and let 'y' be
amount per head which they have to pay.
Then xy = 2400.
or y = 2400/x
Since two friends have forget the purse, x-2 persons should
share the total amount(2400).
If they share, they have to make an extra contribution of
Rs 100 to pay up the bill
That is x-2 persons should pay y+100 each
or (x-2)(y+100) = 2400
or y+100 = 2400/(x-2)
or y = 2400/(x-2) - 100
Therefore we have got two equations namely,
y= 2400/x and y = 2400/(x-2) - 100
Comparing these two, we get
2400/x = 2400/(x-2) - 100
Solving this we get
x^2 - 2x -48 = 0
or (x-8) (x+6) = 0
or x = 8 or x = -6
Since 'x' denote the number of persons, it should be
So, x = 8.
Argentina had football team of 22 player of which
captain is from Brazilian team and goalki from European
team. For remainig palayer they have picked 6 from
argentinan and 14 from european. Now for a team of 11 they
must have goalki and captain so out of 9 now they plan to
select 3 from rgentinian and 6 from European. Find out no.
of methods avilable for it.