Out of nine persons, 8 persons spent ₹30 each for their meals. The ninth one spent 20 more than the average expenditure of all the nine. The total money spent by all of them was :

₹292.50

Let the ninth one spent Rs. x

Spent by 8 persons = 240

      x - \(\frac{240 + x}{9}\) = 20   

( Avg of money spent by 9 persons = \(\frac{240 + x}{9}\)

⇒ Bx = 420

⇒ x = 52.5

Total money spent by all of them = 240 + 52.5 = 292.5