A drinks machine offers three selections - Tea, Coffee or
Random (Either tea or Coffee) but the machine has been wired
up wrongly so that each button does not give what it claims.

If each drink costs 50p, how much minimum money do you have
to put into the machine to work out which button gives which
selection?

Answers were Sorted based on User's Feedback



A drinks machine offers three selections - Tea, Coffee or Random (Either tea or Coffee) but the mac..

Answer / guest

You have to put just 50p.

Put 50p and push the button for Random. There are only 2
possibilities. It will give either Tea or Coffee.

? If it gives Tea, then the button named Random is for Tea.
The button named Coffee is for Random selection. And the
button named Tea is for Coffee.

? If it gives Coffee, then the button named Random is for
Coffee. The button named Tea is for Random selection. And
the button named Coffee is for Tea.

Thus, you can make out which button is for what by putting
just 50p and pressing Random selection first.

Is This Answer Correct ?    52 Yes 13 No

A drinks machine offers three selections - Tea, Coffee or Random (Either tea or Coffee) but the mac..

Answer / fakkad

Guest's answer is correct.

We need only 50p to determine the right buttons.

Is This Answer Correct ?    11 Yes 5 No

A drinks machine offers three selections - Tea, Coffee or Random (Either tea or Coffee) but the mac..

Answer / krishnaveni

now if we put first a 50p at one button,it may be
coffe/tea
assuming it to be coffee,then the button may be either
coffe/random
again inserting coin into same button we may get
tea/coffe.
if it is coffe then it is coffe button orelse if
it is tea it is random button.so one can button is taken
out.now putting one more coin in in any of two buttons,we
can catch stea/coffe.so 1rupe50paise is needed

Is This Answer Correct ?    7 Yes 7 No

A drinks machine offers three selections - Tea, Coffee or Random (Either tea or Coffee) but the mac..

Answer / neha

Put 50p and push the button for Random. There are only 2
possibilities. It will give either Tea or Coffee.

If it gives Tea(assume), then the button named Random is
for Tea.

Put 50p and push the button for Tea. There are only 2
possiblities. It will give either Coffee or Tea.

If it gives Tea, then it confirms that button is
actually 'Random'.

But If it gives coffee, then it may be either coffee or
Random

Again put 50p & push same above button for Tea. This time
if it gives either tea then its actually Random else it is
Coffee.

So it takes 1.5 Rs to confirm the state of 2 buttons.
And as the state of two buttons r confirmed so the 3rd
button state is already confirmed.

Is This Answer Correct ?    4 Yes 4 No

A drinks machine offers three selections - Tea, Coffee or Random (Either tea or Coffee) but the mac..

Answer / ddd

50ps-button1 - coffee (assume)
50ps-button1 - confirm it coffee or random (assume coffee)
50ps-button2 - Tea (assume)
50ps-button2 - confirm it tea or random (assume tea)
Rs 2/- required to confirm which button gives what

Is This Answer Correct ?    3 Yes 15 No

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