<span>a+b=5,
0.1*a+0.25*b=0.2*5
a=5-b
0.1*(5-b)+0.25*b=1
0.5-0.1b+0.25*b=1
0.15*b=0.5
b=3.33333333
a=5-b
a=1.66666667 b=3.33333333</span>
Ok so I heard this question a few times already and couldn't remember how it went so I decided to put my brain to the test, I used my algebra to use and complete it.
If the Earth were shrunk down to the size of a basketball (radius:4.69 inches) the Moon would be a tennis ball (radius: 1.2768 inches, to be exact) 23.5 feet away.
The Sun would be a 42.6-foot sphere (source) located 1.7 miles away.
The closest star, Proxima Centauri, would still be 463,151 miles away – almost twice the distance of the actual moon."
Answer:
36/80 chance of landing on tails, or a 45% chance .