You know from the statement that on Monday he sells 2 pastries, so on Tuesday he sells 3, Wednesday 4, Thursday 5, Friday 6, Saturday 7 and Sunday 8 pastries.
So the average value is (2+3+4+5+6+7+8) pastries/7 days
The baker sells, on average, 35/7= <<35/7=5>>5 pastries/day for 1 week
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