Magic is the answer
please revise your incomplete question next time before you post it
When you are asked to solve an equation, you need to isolate the variable which is t in this case. To isolate t, you would divide both sides by -5 and be left with t=-6 which is the final answer.
I hope this helps.
Event 4 (impossible), Event 3 (probability is 7/20), Event 1 (probability is 6/12 which is greater than 7/20), and Event 2 (certain to happen)