Answer:
90
Explanation:
Using inequalities we can understand this problem.
First call X the number of products in the original batch
Then X/6 is the number of muffins in each tray before putting the croissants
Finally, X/6+5 are the products in each tray counting the croissants, and this quantity at least should be 20, it means:
![(X)/(6)+5\geq 20](https://img.qammunity.org/2020/formulas/mathematics/high-school/6qfcqj7e1mc7cykbcvxecn8wnmmj0fue3t.png)
Isolating X:
![(X)/(6)\geq 20-5\\(X)/(6)\geq 15\\X\geq 6*15\\X\geq 90](https://img.qammunity.org/2020/formulas/mathematics/high-school/hin05a5spdqap6s2mxtxjap6uplxdpvnpl.png)
The least possible number of muffins in the baker's original batch is 90.