ChandlerBong
G number of girls and B number of boys are students of a school S. A test is conducted in the school. If all students of school S appeared in the test, is the ratio of students who pass the test to the ratio of students who fail more for girl students than for the entire school S?
(A) The ratio of the number of students who pass to the number of students who fail is more for boy students than for the entire school.
(B) Less than 3/7 of the total students who pass the test are girls and less than 13/25 of the total students who fail the test are boys.
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Representations - Boys Passed = \(B_P\)
- Boys Failed = \(B_F\)
- Girls Passed = \(G_P\)
- Girls Failed = \(G_F\)
Question\(\frac{G_P}{G_F} > \frac{B_P + G_P}{B_F + G_F}\)
Cross multiplying as the numbers are positive
\((G_PB_F) + (G_PG_F)> (B_PG_F) +(G_FG_P) \)
Substracting \(G_FG_P\) from both sides
\( (G_PB_F)> (B_PG_F)\)
or
\(\frac{B_F}{G_F} > \frac{B_P}{G_P} \)
This is our target question.
Statement 1(A) The ratio of the number of students who pass to the number of students who fail is more for boy students than for the entire school.\(\frac {B_P}{B_F} > \frac{B_P+G_P}{B_F+G_F}\)
Cross multiplying as the numbers are positive
\((B_PB_F)+(B_PG_F) > (B_FB_P)+(G_PB_F)\)
Substracting \(B_FB_P\) from both sides
\((B_PG_F) > (B_FG_P)\)
The equation matches the target question, hence this statement is sufficient. We can eliminate B, C, and D.
Statement 2(B) Less than 3/7 of the total students who pass the test are girls and less than 13/25 of the total students who fail the test are boys.Less than 3/7 of the total students who pass the test are girls
\(\frac{G_P}{G_P + B_P} < \frac{3}{7}\)
\(7G_P < 3G_P + 3B_P\)
Substracting \(3G_P\) from both sides we get,
\(4G_P < 3B_P\)
\(\frac{G_P}{B_P} < \frac{3}{4} \implies\) \(\frac{B_P}{G_P} > \frac {4}{3} \)
\(\approx \frac{B_P}{G_P} > 1.33 \)
less than 13/25 of the total students who fail the test are boys.
\(\frac{B_F}{G_F + B_F} < \frac{13}{25}\)
\(25 B_F < 13G_F + 13B_F\)
Substracting \(13B_F\) from both sides we get,
\(12 B_F < 13G_F \implies\) \(\frac{B_F}{G_F} < \frac {13}{12} \)
\(\approx \frac{B_F}{G_F} < 1.08\)
Therefore we can conclude that
\(\frac{B_F}{G_F} < \frac{B_P}{G_P} \)
This information is sufficient as well.
Option D