A bat and ball cost $1.10.
The bat costs one dollar more than the ball.
How much does the ball cost?
The bat costs one dollar more than the ball.
How much does the ball cost?
50% of harvard students got this question wrong
- Thread starter Zoot Allures
- Start date
Reason is many people are overconfident, prone to place too much faith in their intuitions. They apparently find cognitive effort at least mildly unpleasant and avoid it as much as possible.
5 cents but intuitive answer is 10 cents
u got it right because you knew it had to be thought out
5 cents but intuitive answer is 10 cents
u got it right because you knew it had to be thought out
I knew the answer was $.05 because I went to a Canadian university and not Harvard, MIT or Princeton.
This website goes further make conclusions about religious folk vs non religious.
http://www.relativelyinteresting.com/the-bat-and-a-ball-problem/
Then posts another interesting but easy one.
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?
A) 24 days
B) 47 days
C ) 48 days
D) 49 days
E) none of the above (state your answer and why)
http://www.relativelyinteresting.com/the-bat-and-a-ball-problem/
Then posts another interesting but easy one.
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?
A) 24 days
B) 47 days
C ) 48 days
D) 49 days
E) none of the above (state your answer and why)
This one is logarithmic progression which is difficult for most people figure out even when they grasp the concept.
Indeed. In both cases the logic of the deriving the answer seems easy because of the simple numbers used.
Expressing the problem as an equation however... especially the progression one can become quite a task for many.
As this is very basic math I highly doubt 50% of Harvard (or even community college) gets this wrong
Its funny noone actually solved it yet though?
(1+x)+x=1.10
1+2x =1.10
2x=0.10
X=0.05
It's just L=2^d
L is number of lily pads, d is number of days.
They are saying 2^48 is the total number of lily pads in the lake. On the 47th day, it would be 2^47, which is half of the total.
An explanation more in line with basic algebra would go
cost of ball = L
cost of bat = T
The two conditions are simultaneous equations:
(A) T + L = 1.10
(B) T = L + 1
substituting (B) into (A),
L + 1 + L = 1.10
so 2L = 0.1 or L=0.05.
back in (B), T = 1.05
