please answer this

Question

A certain voltmeter has an internal resistance of 10,000  and a range from 0 to 100 V. To

give it a range from 0 to 1000 V, one should connect:

A) 100,000  in series

B) 100,000  in parallel

C) 1000  in series

D) 1000  in parallel

E) 90,000  in series

Answer 1

The answer is d) 90 000 ohm in series.

The key equation is 1000 = (R + 10 0000) [ 100 / 10 000]

Solving for R gives R = 90 000 ohms