Answer:
13 hours and 5 minutes is right
Mass=5.6
Find this by plugging your values into the density formula and solving for M.
3.5 cubic centimeters is also equivalent to 3.5 ml
A) No solutions, because the number under the square root symbol in the quadratic equation (b^2 - 4ac) is negative.
B) One solutions, because the number under the square root symbol in the quadratic equation (b^2 - 4ac) is equal to 0.
The mnemonic SOH CAH TOA helps you remember that
... Sin = Opposite/Hypotenuse
The side opposite angle K is marked with length 5. The hypotenuse KM is marked with length 10. Using the above relationship ...
... sin(∠K) = 5/10 = 1/2
The first choice is appropriate: 
