P(f | weekend) = p(f & weekend)/p(weekend)
.. = 10%/25%
.. = 2/5 = 0.4
If I could give you an answer, I would. But I'm terrible at Math so, sorry
The best estimate would be 121/15 = 8.1
We do like the following:
Set the first number is a and the second is b.
We have two equations: a+2xb=24, 2xa+b=21
And we have 2xa+4xb=48 or 2xa=48-4xb
So: 48-4xb+b=21 or -3xb=21-48=-27 and we got b=-27:(-3)=9 and a= 6
a=6 and b=9
