On 5 September to 8 September, an average of 49 daisies were sold and from 9th September to 13 September, an average of 29 daisies were sold. $316 worth of daisies were sold from 14 September to 24 September. Given that a daisy was sold for $4, find the average number of daisies sold from 5 September to 24 September.
Number of daisies sold from 14 September to 24 September
= 316 ÷ 4
= 79

Number of days from 5 September to 8 September
= 8 - 5 + 1
= 4

Number of days from 9 September to 13 of September
= 13 - 9 + 1
= 5

Total number of daisies sold
= (4 x 49) + (5 x 29) + 79
= 196 + 145 + 79
= 420

Number of days from 5 September to 24 September
= 24 - 5 + 1
= 20

Average number of daisies sold
= 420 ÷ 20
= 21

Answer(s): 21