The answer is 50 i. e. C

Explanation:

If the potentiometer is assumed to be linear

Then one one quarter of the total resistance will be below the slider and three quarters of the resistance will be above the slider.

To get zero voltage reading, 150 must be 3/4 of the total resistance of the right leg

150 = 0.75(150 + R)

150 = 112.5 + 0.75R

37.5 = 0.75R

R = 50 Ω

answer: pseudoscience

the total distance that martina travels that day is

(distance from home to mom's office) plus (distance from mom's office to school)

plus (distance from school to library) plus (distance from library to friend's house)

plus (distance from friend's house to martina's house).

(we don't know what any of these distance actually is.)