A drinks machine offers three selections - Tea, Coffee or Random but the machine has been wired up wrongly so that each button does not give what it claims. If each drink costs 5 rupees, how much minimum money do you have to put into the machine to work out which button gives which selection?

• 5
  put the Rs in the button named random
  u will find it gives either tea/coffee
  the button named tea/coffee gives coffee/tea respectively...
• 10 years agoHelpfull: Yes(2) No(2)
• 15rs
  
  
  put 5 in 1st button if it gives coffe,then either it gives only coffe or random
  again put 5 in 2nd if it gives coffe,then either it gives only coffe or random
  now, put 5rs in 1st if it gives again coffe,then 1 st button gives only coffe, 2 nd button gives random and 3rd gives only tea.
• 10 years agoHelpfull: Yes(1) No(1)