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NED HELP FAST!!!!!!!!!!!

John the trainer has two solo workout plans that he offers his clients: Plan A and Plan B. Each client does either one or the other (not both). On Friday there were 3 clients who did Plan A and 5 who did Plan B. On Saturday there were 9 clients who did Plan A and 7 who did Plan B. John trained his Friday clients for a total of 6 hours and his Saturday clients for a total of 12hours. How long does each of the workout plans last?

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Answer:

They are both the same at 3/4 of an hour

Explanation:

We have a system of equations here. The first one is for Friday:

3A + 5B = 6, which says that 3 people at the number of hours for plan A plus 5 people at the number of hours for plan B equals 6 hours total.

The second equation is for Saturday:

9A + 7B = 12, which says that 9 people at the number of hours for plan A plus 7 people at th number of hours for plan B equals 12 hours total.

We can solve this easily using the addition/elimination method. Begin by multipying the first equation through by a -3 to eliminate the A's. That gives you a new first equation of:

-9A - 15B = -18

9A + 7B = 12

You can see that the A's are eliminated, and adding what remains leaves us with

-8B = -6 so

B = 3/4 hour

Now we can sub that back in for B in either one of our original equations to solve for A. I changed the 3/4 to .75 for ease of multiplying:

9A + 7(.75) = 12 and

9A + 5.25 = 12 and

9A = 6.75 so

A = .75 which is also 3/4 of an hour

User Praneet Nadkar
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