4. In the Department of Natural Sciences, 14 faculty members have a PhD, and 30 faculty members do not have a PhD. In the Department, the number of female faculty who do not
have a PhD is 10 more than the number of females who have a PhD. If a third of the male
faculty in the Department have a PhD, then what is the number of female faculty in the

  8

Step-by-step explanation:

We can start by making the table below to show the given numbers (red) and to assign a variable (x) to the number we want to find: female PhDs.

By subtracting the female numbers from the totals, we can find the corresponding numbers of male PhDs and non-PhDs.

The number of male non-PhDs is twice the number of male PhDs, so we have ...

  2(14 -x) = 20 -x

  28 -2x = 20 -x . . . . eliminate parentheses

  8 = x . . . . . . . . . . . .add 2x-20

The number of female faculty with PhDs is 8.

+25 = x

step-by-step explanation:

here x is the hypotenuse of a right triangle whose legs are 7 and 24.   by the pythagorean theorem, 7² + 24² must equal x²:

x² = 49 + 576 = 625.   thus, x = +√625 = +25 = x