Question 636450
Let
Present age of Paul = p years old
Present age of Wendy = w years old


Paul is 11 years younger than Wendy.
w=p+11............(1)
In 10 years,
Paul will be = p+10 years old
Wendy will be = w+10 years old
Then
Wendy will be twice as old as  Paul
w+10=2(p+10)
w+10=2p+20
w=2p+20-10
w=2p+10................(2)
Put the value of w from (1) to (2)
p+11=2p+10
p-2p=10-11
-p=-1
p=1
Put the value of p in (1)
w=p+11............(1)
w=1+11
w=12


Present age of Paul = p = 1 year old
Present age of Wendy = w = 12 years old