The average daily production of toys in a factory in the month of December is 512. If the average production during first 20 days is 515 and that of the last 13 days is 510, then what is the average of production on 19 and 20 December?

529

Total production of toys in a factory in the month of December = 31 x 512 =15872

Total production of toys in a factory in the first 20 days = 20 x 515 = 10300

Total production of toys in a factory in the Last 13 days = 13 x 510 = 6630

Total production of toys in a factory in the 19th and 20th Day = 10300 + 6630 - 15872 = 1058

Avg. production of toys in a factory in the 19th and 20th Day = 529