let x be the numbers of student
let y be the original amount contributed per student
25,000 = x(y)
x=25,000/y
if there had been 25 members more in the club each would have contributed Php50 less the
[tex]25,000=(x+25)(y-50)[/tex]
[tex]25,000= (\frac{25,000}{y} + 25) (y-50)[/tex]