Answer: The correct answer for the fill in the blank is 600
Explanation-
As per the question, the magnification of high power objective [tex](m_{o} )[/tex] = 40x
Magnification of eye piece [tex](m_{e} )= 15x[/tex]
Total magnification
[tex]m= m_{o} \times m_{e}[/tex]
Putting the values of [tex]m_{o}\text{ and }m_e[/tex]
= 40×15
= 600
Thus, total magnification= 600x
