Mr. Kumar drives to work at an average speed of 48 km/h. The time taken to cover the first 60% of the distance is 10 minutes more than the time taken to cover the remaining 40%. What is the total distance to his workplace
Question:
Mr. Kumar drives to work at an average speed of 48 km/h. The time taken to cover the first 60% of the distance is 10 minutes more than the time taken to cover the remaining 40%. What is the total distance to his workplace?
Solution:
- Let the total distance to work be DD kilometers.
The first part of the journey is 60% of the distance, so:Distance for the first part=0.6D\text{Distance for the first part} = 0.6DThe second part of the journey is 40% of the distance:
Distance for the second part=0.4D\text{Distance for the second part} = 0.4D
- Time taken for each part of the journey:
Using the formula Time=DistanceSpeed\text{Time} = \frac{\text{Distance}}{\text{Speed}}, the time for each part is:- Time for the first part:
T1=0.6D48T_1 = \frac{0.6D}{48}
- Time for the second part:
T2=0.4D48T_2 = \frac{0.4D}{48}
- Time for the first part:
- Given condition:
The time for the first part is 10 minutes more than the time for the second part. Convert 10 minutes to hours:10 minutes=1060=16 hours10 \, \text{minutes} = \frac{10}{60} = \frac{1}{6} \, \text{hours}So:
T1=T2+16T_1 = T_2 + \frac{1}{6}
- Substitute the values of T1T_1 and T2T_2:
0.6D48=0.4D48+16\frac{0.6D}{48} = \frac{0.4D}{48} + \frac{1}{6}
- Simplify the equation:
Multiply through by 48 to eliminate the denominator:0.6D=0.4D+80.6D = 0.4D + 8Subtract 0.4D0.4D from both sides:
0.2D=80.2D = 8
- Solve for DD:
D=80.2=40 kmD = \frac{8}{0.2} = 40 \, \text{km}
Answer:
The total distance to Mr. Kumar’s workplace is 40 kilometers.