Answer:
4/69 to be exact. Slightly greater than 1/18
Step-by-step explanation:
The chance of selecting the PB cookie on the first try is 4 out of 24 or 1 out of 6. There are now 23 coolies left; 8 are chocolate, so 8/23 chance. (Slightly greater than 1/3) The chance of both events happening is the product if the individual events' chances. So multiply 1/6 times 8/23 to get 8/138. That reduces to 4/ 69. If he had put that first cookie back, the multiplication would have been 1/6×1/3. A lot easier.
Answer:
15%
Step-by-step explanation:
90-75=15
Given that this is based on simple interest, in the first case, investing at 4% for 3 years gives a total interest of 4%*3 = 12%. In the second case, investing at 6% for 4 years gives a total interest of 6%*4 years = 24%. (We can do this since the same principal is given to both.) This is exactly double that of the first case of 12%, so the second choice is the right answer.
I believe the number is -1