128k views
0 votes
Alina and Sophia can finish a plowing job in six hours if they work together . Alina can do the job in 10 hours by herself . how long would it take Sophia to finish her job alone

1 Answer

3 votes
Let's use the formula:

1/T = 1/A + 1/B

where T is the time it takes for both Alina and Sophia to finish the job working together, A is the time it takes for Alina to finish the job alone, and B is the time it takes for Sophia to finish the job alone.

We know that:

T = 6 hours (since they can finish the job together in 6 hours)
A = 10 hours (since Alina can finish the job alone in 10 hours)

Now we can plug in these values and solve for B:

1/6 = 1/10 + 1/B

Multiplying both sides by 30B, we get:

5B = 3B + 15

Subtracting 3B from both sides, we get:

2B = 15

Dividing both sides by 2, we get:

B = 7.5

So Sophia can finish the job alone in 7.5 hours.

Hopes this helps!
User Gordon Glas
by
8.7k points