<PRE><B>Question 1189190</B>
you have 15 girls and x boys.
total of girls and boys = 15 + x.
x is the number of boys.


the girls average 20 stamps each.
the boys averaged 14 more each for a total of 34 each.


the average of the boys and the girls together is 28.


the equation you need to solve is:


20 * 15 + 34 * x = 28 * (15 + x)
simplify to get:
300 + 34 * x = 420 + 28 * x
subtract 28 * x from both sides of the equation and subtract 300 from both sides of the equation to get:
34 * x - 28 * x = 420 - 300
combine like terms to get:
6 * x = 120
solve for x to get:
x = 120 / 6 = 20


this says that the number of boys is 20.
15 girls plus 20 boys = 35 children.
15 * 20 + 20 * 34 = 300 + 680 = 980 collected stamps.
980 / 35 = average of 28 stamps per child.


numbers look good.
solution is that there were 35 children.





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