Cognitive Reflection Test

Here are several items that vary in difficulty. Answer as best as you can.

Question 1:
In a lake, there is a patch of lily pads. Every day, the patch doubles in size. If it takes 48 days for the patch to cover the entire lake, how long would it take for the patch to cover half of the lake?
24 days
12 days
47 days
36 days
Question 2:
A bat and a ball cost £1.10 in total. The bat costs £1.00 more than the ball. How much does the ball cost?
1 pence
5 pence
10 pence
9 pence
Question 3:
If it takes 5 machines 5 minutes to make 5 widgets, how long would it take 100 machines to make 100 widgets?
500 minutes
20 minutes
100 minutes
5 minutes
Random answers selected!