9514 1404 393
Answer:
Β 6
Step-by-step explanation:
Let p, b, j, d represent the ages of Phil, Bill, Jenny, and Dad. We are given the relations ...
Β b = 2p
Β j = b -2
Β 2(p +b +j) = d
Β (p+9) +(b+9) +(j+9) = d+9
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Solving the last equation for d, we get ...
Β (p +b +j) +18 = d
Substituting for the sum of p, b, j in the third equation, we have ...
Β 2(d -18) = d
Β d = 36 . . . . . . . . add 36-d
Substituting for b and j in the third equation, we get ...
Β 2(p +(2p) +(2p-2)) = 36 . . . . . Β uses b=2p in the 2nd equation
Β 10p -4 = 36 . . . . . . . . . . . . . . . collect terms
Β p = 40/10 = 4 . . . . . . add 4; divide by 10
Β b = 2p = 8
Β j = b -2 = 6
Jenny's current age is 6.
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All of the ages are ...
Β Bill: 8; Jenny: 6; Phil: 4; Dad: 36
