Very easy to do this.
60/12 is your fraction.
Multiply numerator and denominator by the same number.
60*2/12*2 = 120/24
120/24 = 5
You can also simplify.
60/12 = 5
12/12 = 1
5/1 = 5
60/12 = 5
These are independent events so
P(A and B) = P(A) * P(B)
Therefore
P(Both gears fail) = 0.05 * 0.08 = 0.004 or 0.4%
Total bill-$67.95
each friends owes about $16.99
Y will equal 36. You can figure this out because you know y is double the value of x. If x is 18,you can just multiply it by 2, which equals 36