Sam goes to school from his house at a speed of 5 kmph and returns at a speed of 4 kmph. If he takes 9 hours in going and coming , what the distance between his house and school?15 km20 km30 km25 kmNone

Let's denote the distance between Sam's house and his school as D (in km).

When Sam goes to school, he travels at a speed of 5 km/h, so the time he spends is D/5 hours.

When he returns home, he travels at a speed of 4 km/h, so the time he spends is D/4 hours.

According to the problem, the total time Sam spends going to school and coming back is 9 hours.

So, we can write the equation: D/5 + D/4 = 9.

To solve this equation, we first need to find a common denominator for 5 and 4, which is 20.

So, we multiply the terms of the equation by 20, getting: 4D + 5D = 180.

This simplifies to 9D = 180.

Finally, we divide both sides of the equation by 9 to find D: D = 180/9 = 20 km.

So, the distance between Sam's house and his school is 20 km.

Let's denote the distance between Sam's house and his school as D (in km).

When Sam goes to school, he travels at a speed of 5 km/h, so the time he spends is D/5 hours.

When he returns home, he travels at a speed of 4 km/h, so the time he spends is D/4 hours.

According to the problem, the total time Sam spends going to school and coming back is 9 hours.

So, we can write the equation: D/5 + D/4 = 9.

To solve this equation, we first find a common denominator for 5 and 4, which is 20.

So, the equation becomes: 4D/20 + 5D/20 = 9, which simplifies to 9D/20 = 9.

Solving for D, we find that D = 20 km.

So, the distance between Sam's house and his school is 20 km.

Let's denote the distance between Sam's house and school as D (in km).

We know that the time it takes to travel a certain distance is equal to the distance divided by the speed.

So, the time it takes Sam to go to school is D/5 and the time it takes him to return home is D/4.

According to the problem, the total time for both trips is 9 hours.

So, we can set up the following equation:

D/5 + D/4 = 9

To solve for D, we first need to find a common denominator for the fractions, which is 20 in this case.

So, the equation becomes:

4D/20 + 5D/20 = 9

Simplifying this gives:

9D/20 = 9

Multiplying both sides of the equation by 20/9 gives:

D = 20

So, the distance between Sam's house and school is 20 km.

Let's denote the distance between Sam's house and his school as D (in km).

When Sam goes to school, he travels at a speed of 5 km/h, so the time he spends is D/5 hours.

When he returns home, he travels at a speed of 4 km/h, so the time he spends is D/4 hours.

According to the problem, the total time Sam spends going to school and coming back is 9 hours.

So, we can set up the following equation:

D/5 + D/4 = 9

To solve this equation, we first need to find a common denominator for 5 and 4, which is 20.

So, we multiply each term by 20:

4D + 5D = 180

This simplifies to:

9D = 180

Finally, we divide each side by 9 to solve for D:

D = 180 / 9

D = 20 km

So, the distance between Sam's house and his school is 20 km.