If 12x2 - ax + 7 = ax2 + 9x + 3 has only one (repeated) solution, then the positive integral solution of a is:
Raj takes 2 \( \frac{1}{3} \) hours to complete a certain distance at a speed of 51 km/hr. What time would Kiran take to complete the same distance at a speed of 68km/hr?
2 hours
1 \( \frac{3}{4} \) hours hours
1 \( \frac{1}{2} \)hours
1 \( \frac{2}{3} \) hours