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Question 970486: The ratio of girls to boys in Liza's classroom is 5 to 4. How many girls are in her classroom if there is a total of 27 students?
Found 3 solutions by lwsshak3, n2, josgarithmetic:
Answer by lwsshak3(11628)   (Show Source):
You can put this solution on YOUR website! The ratio of girls to boys in Liza’s classroom is 5 to 4. How many girls are in her classroom if there is a total of 27 students?
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let x=number of girls in Lisa's classroom
27-x=number of boys in Lisa's classroom
..
5(27-x)=4x
135-5x=4x
9x=135
x=15
number of girls in Lisa's classroom=15
Answer by n2(91) (Show Source):
You can put this solution on YOUR website! .
The ratio of girls to boys in Liza's classroom is 5 to 4. How many girls are in her classroom
if there is a total of 27 students?
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It can be solved mentally without using equations.
According to the problem, we can group the students in sets, each containing 5 girls and 4 boys.
Each such group has 5 + 4 = 9 students.
So, the number of such groups is 27/9 = 3.
Thus, the number of girls in the class is 3*5 = 15. ANSWER
Solved.
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In normal teaching process, the students should learn this grouping method first,
allowing to solve this problem mentally (at 4-th or 5-th grade).
Later, in 6-th or 7-th grade, students will learn proportions and will solve such problems using proportions.
But for normal mathematical development, students should learn the mental solution way first,
using the grouping method.
Answer by josgarithmetic(39835) (Show Source):
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