If the geometric mean of a and 120 is 60, find the value of a.

Answer:
The answer is option 4.
Step-by-step explanation:
Given that the mean formula is total score/number of score. So we can assume that total score is (a+120), number of score is 2 and the mean value is 60. Then you have to find the value of a :
[tex] \frac{a + 120}{2} = 60[/tex]
[tex]a + 120 = 60 \times 2[/tex]
[tex]a + 120 = 120[/tex]
[tex]a = 120 - 120[/tex]
[tex]a = 0[/tex]
[tex] \text{ Geometric mean of two numbers } a \text{ and } b , \text{ where } a,b>0 \text{ is given by } G= \sqrt{ab}[/tex]
[tex] \sqrt{a\cdot120}=60 [/tex]
[tex] \implies 60 \cdot 2 \cdot a=60\cdot 60 \qquad \text{Squaring both sides} [/tex]
[tex] \implies a =30 [/tex]