Eleven friends spend Rs 18 each on a tour and the twelfth friend spend Rs 11 less than the average expenditure of all twelve of them. What is the total money spent by twelve friends?

Rs 204

Average expenditure of eleven friends = Rs 18 (each spends the same amount) 

Let the expenditure of the twelfth person be Rs x, 

According to the question,

   x = $\frac{18\times11\; +\; x}{12}$ - 11

12x + 12x11 = 198 + x 

11x = 66   ⇒ x = 6

total money spend by twelve friends = 18x11 + 6 = Rs 204