In covering a certain distance, the speeds of A and B are in the ratio of 3 ∶ 4. A takes 20 minutes more than B to reach the destination. The time taken by A to reach the destination is
1
\(\rm 1\frac{1}{4}\ hours\)
2
\(\rm 1\frac{1}{3}\ hours\)
3
2 hours
4
\(\rm 2\frac{1}{2}\ hours\)