10x+x+3=4(x+x+3)
Solution: x = 3
x+3=3+3=6
This two-digit number is 36.
2. After setting X hours, car B will catch up with car A. ..
72x= 48×(x+25/60)
Solution: x = 5/6
After 5/6 hours, the B car caught up with the A car. ..