SOLUTION: A class has 27 pupils of whom ‘x’ are boys. a) How many girls (in terms of x) are there in the class? b) If the number of girls is twice the number of boys, find the value of

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: A class has 27 pupils of whom ‘x’ are boys. a) How many girls (in terms of x) are there in the class? b) If the number of girls is twice the number of boys, find the value of       Log On


   



Question 1014044: A class has 27 pupils of whom ‘x’ are boys.
a) How many girls (in terms of x) are there in the class?
b) If the number of girls is twice the number of boys, find the value of x.

Found 2 solutions by fractalier, josmiceli:
Answer by fractalier(6550) About Me  (Show Source):
You can put this solution on YOUR website!
a) 27 - x are girls.
b) We set this up as 27-x = 2x and we get 27=3x and x = 9.

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+x+ = number of boys
(a)
+27+-+x+ = number of girls
(b)
+27+-+x+=+2x+
Add +x+ to both sides
+3x+=+27+
+x+=+9+
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Notice that there must be +18+ girls
and +9+%2B+18+=+27+