HeLp..word porblems..?

Question

how to solve this probLEms?

A. a man starts from A at 2:00pm and travels to B at a rate of 30mi/h.After resting at B for one hour,he returns over the same route at a rate of 40mi/h and arrives at A at 6:30pm .Determine the distance between A and B?

b.A swimming pool ca n be filled in 6hours and requires 9 hours to drain.if the drain was accidentally left open for 6hours while the pool was being filled,how long did filling the pool required?

tHAnkzzz..in aDvance!!

Answer 1

Math questions. It's better to repost over there.

Answer 2

I am not sure what this has to do with anthropology, but...

Jeff gave you a good answer for A.  This distance is 60 miles and you can test this with the trip from A to B took 2 hours (60/30 = 2).  One hour to rest (total of 3 hours).  The trip from B to A took 1.5 hours (60/40 = 1.5) giving a total time for the whole trip of 4.5 hours.

For B.  Let V equal the volume of the pool.  V/6 is the rate of filling the pool and V/9 is the rate for emptying the pool.

The time with the drain open = 6 hours, so the amount removed from the pool would be V/9 * 6 = (2/3)*V.

The total volume of water pumped into the pool would be V + (2/3)*V or (5/3)* V.  The rate for filling was V/6. so the total time is

[(5/3)* V] / [V/6] = 10 hours.

Answer 3

Here is how you solve the first question:

The whole trip took 4.5 hours but since he rested for one hour

the actual ride took 3.5 hours

time = distance/speed

so

if x=distance

3.5= x/30+x/40

so

3.5= 4x / 120 + 3x / 120

so

3.5=7x / 120

so

3.5x120= 7x

so

420=7x

so the distance is:

x= 60miles