<PRE><B>Question 164856</B>
Let the number of boys be b.
Original share=2000/b
Share of additional cost=420/(b-1) 
2000/b - 420/(b-1) = 190
2000(b-1)-420b=190(b^2-b) multiply each side by the LCM.
2000b-2000-420b=190b^2-190b
200b-200-42b=19b^2-19b divide each side by 10.
19b^2-177b+200=0 Subtract the left side from the right.
b=8
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Ed
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*[invoke solve_quadratic_equation 19, -177, 200]</PRE>