There is a 30 % chance of rain and a 70% chance of shine. If it rains there is a 50% chance that Bob will cancel his picnic but if the sun is shining he will definitely have his picnic. What is the chance that Bob will have his picnic?	Pick: A) 70 % B) 75 % C) 80 % D) 85 % E) 90 %
Chance of no picnic+chance of picnic= 100% ... (i)   Chance of picnic=100%-Chance of no picnic ... (ii)   Chance of no picnic= 50% of 30%= 15%   Therefore, According to (ii), Chance of picnic= 100%-15%= 85%.   Answer 85 %100 -15= 
<gadget id="calculator">100 -15</gadget>
<output>85</output>
85%.   Answer 85 %
<result>D</result>
There is a 30 % chance of rain and a 70% chance of shine. If it rains there is a 50% chance that Bob will cancel his picnic but if the sun is shining he will definitely have his picnic. What is the chance that Bob will have his picnic?