Hari travels from City A to City B. If Hari drives his car at 2/3 of his normal speed, then he reaches City B 30 minutes late. Find the time (in minutes) that Hari would have taken to travel from City A to City B if he drove at his normal speed.

Correct option is C

Given:
Hari drives at (2/3) of his normal speed.
Delay = 30 minutes.
Solution:
Let Distance = D and Normal Speed = S.
New Speed = $$\frac 23 S$$​​
Time at New Speed =$$\frac{D}{\left(\frac{2}{3}\right) \times S}$$​​
Time at Normal Speed = $$\frac{D}{S}$$​​
​$$\text{Difference in time} = \frac{D}{\left(\frac{2}{3}\right) \times S} - \frac{D}{S} = 30\\\ \\\Rightarrow \frac{3D}{2S} - \frac{D}{S} = 30\\\ \\\Rightarrow \frac{3D - 2D}{2S} = 30\\\ \\\Rightarrow \frac{D}{2S} = 30\\\ \\\Rightarrow \frac{D}{S} = 60$$​​