S={ 11 12 13 14 15 16 17 18
21 22 23 24 25 26 27 28
31 32 33 34 35 36 37 38
41 42 43 44 45 46 47 48...
.......}
P(e)=(1+2+3+4+5+6)/64
=21/64=0.328(B)
Let's say the speed of the plane is "p", and the speed of the wind is "w".
when the plane goes with the wind, is not really going "p" mph fast, is really going "p + w" mph fast, because the wind is adding speed to it.
likewise when the plane is going against the wind, is also not going "p" fast is going "p - w" mph fast. Therefore,
5^4 (five to the 4th power)
he ended with 16
he earned 6 for mowing the lawn, so before mowing the lawn he had 16-6 =10
he spent half on pizza and had 10 left so allowance = 10*2 = 20
he gets $20 a week for allowance