30 people went to a restaurant for a dinner party, 20 of them paid Rs. 880 each and each of the rest of them paid Rs.110 more than the average of the total expenses, what was the total expense (in Rs) for the dinner?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 28050
Average = Sum of all observation/Number of observation
Let the Average bill per person be ' x ' Rs
Bill for 20 people = 20 × 880 = Rs.17600
Total bill paid by other 10 people
⇒ 10(x + 110)
⇒ 10x + 1100
Total bill paid = 17600 + 10x + 1100
⇒ 18700 + 10x
According to question
Average bill = (18700+10x)/30 (Average = Sum of observations/No. of observations)
⇒ 30x = 18700 + 10x
⇒ 20x = 18700
⇒ x = Rs 935
Total bill paid = 30 × x
⇒ 30× 935
⇒ Rs. 28050