Total number of students=50
Number of boys=2x
Number of girls=y
total will be:
2x+y=50
⇒y=50-2x
when (y-6) boys left the auditorium the new number of boys was:
2x-(y-6)
=2x-y+6
but y=50-2x
thus the new number will be:
2x-(50-2x)+6
=4x-44
when (2x-5) girls left the auditorium the remaining number will be:
y-(2x-5)
=y-2x+5
but
y=50-2x
thus the new number of girls will be:
50-2x-2x+5
=55-4x
new total number of students:
(55-4x)+(4x-44)
=11
probability of selecting a girl at random will be:
(55-4x)/11=9/13
13(55-4x)=9*11
715-52x=99
616=52x
x=12
thus
y=50-12=38
thus
x=12 and y=38
Answer:
D. StartFraction negative 1 + StartRoot 3 EndRoot Over 2 EndFraction
Step-by-step explanation:
Multiply numerator and denominator by the conjugate of the denominator. Then the denominator is the difference of squares, which will be rational. This simplification is called "rationalizing the denominator."
