Bat and Ball

Let’s start with a few quick puzzles. I want you to answer fast, so go with your gut, and don’t overthink it. Just give the first answer your brain comes up with. Ready? Click start to begin.

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Part 1:

Thinking, Fast and Slow

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Answers

1) A tech company is offering 100 Motorola phones and 10 Samsung phones. How many phones are they offering in total? Correct answer: 110 1) 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? Correct answer: 5¢ 2) It takes 5 paperclip machines 5 seconds to make 5 paperclips. How long would it take 100 paperclip machines to make 100 paperclips? Correct answer: 5 seconds 3) 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? Correct answer: 47 days

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If you got some of those questions wrong then don't panic, you're in good company! The majority of people get those questions wrong. And not just anyone: university students, professionals, people who consider themselves strong critical thinkers (Frederick, 2005). Indeed, some people won't even accept the correct answer after it is shown to them! So what’s actually going on? Why does your brain nail some problems and completely fail on others?

Your brain sees "half" and "48 days" and immediately suggests 24 — that's how halving normally works. But the patch doubles each day. So the day before it covers the whole lake, it must have covered exactly half. Day 48 = full lake. Day 47 = half the lake.

This is simple addition: 100 + 10 = 110. The numbers and the question structure don't create any false pattern. Your insticts get this one right. Let's see if the other questions will be so straightforward!

Your brain sees "$1.00 more" and quickly substitutes "the bat costs $1.00." But that's not what the question says. If the ball costs 10¢ and the bat costs $1.00 more than the ball, the bat would cost $1.10 — making the total $1.20, not $1.10. The correct solution is ball = 5¢, bat = $1.05 (which is exactly $1.00 more than 5¢), total = $1.10. This famous riddle is known as the "bat and ball problem" and is discussed at length in Daniel Kahneman's 2011 book, Thinking, Fast and Slow.

Your brain spots the pattern 5-5-5 and assumes everything scales together to 100-100-100. But look again: if 5 machines make 5 paperclips in 5 seconds, each machine makes 1 paperclip in 5 seconds. So 100 machines would each make 1 paperclip in 5 seconds — that's 100 paperclips in 5 seconds.

Source: Reddit