A) 65 mm
B) 60 mm
C) 70 mm
D) None of these
Correct Answer: B
Solution :
Here, change in time = 20 and \[\frac{a}{b}=\frac{3}{4}\] We have, change in time \[=\,\left( \frac{b}{a}-a \right)\times \] Original time \[\therefore \] Original time \[=\frac{\text{Charge}\,\text{in}\,\text{time}}{\left( \frac{b}{a}-1 \right)}\] \[=\frac{20}{\left( \frac{4}{3}-1 \right)}=60\,\min \]You need to login to perform this action.
You will be redirected in
3 sec