We want to write the ratio of 40 days to 5 weeks as a fraction. Both values must have the same unit. Let us convert 5 weeks to days. Recall,
1 week = 7 days
5 weeks = 5 x 7 = 35 days
Thus, the ratio as a fraction would be
40/35
Dividing the numerator and denominator by 5, the fraction in the simplest form would be 8/7