\(Two \) Mangoes, \(three \) grapes and \(four \) apples cost \(Rs. 15.\) \(Three\) Mangoes, \(two\) grapes and \(one\) apple cost \(Rs. 10.\) I bought \(3\) Mangoes, \(3\) grapes and \(3\) apples. How much did I pay?
Answer: B
Mango \(= X;\) Grape \(= Y;\) Apple \(= Z;\)
\(2X + 3Y + 4Z= 15 - 1\)
\(3X + 2Y + Z = 10 - 2\)
Adding (1) and (2) \(5X + 5Y + 5Z = 25\)
Clearly, \(X + Y + Z = 5\)
So cost of \(3\) Mangoes, \(3\) Grapes and \(3\) Apples will be \(3X + 3Y + 3Z \) \(i.e, 15\)