A flea collar for dogs contains an active ingredient that evaporates at a rate propor- tional to the amount still presen
Posted: Sat Jul 09, 2022 12:01 pm
A. 16.83
B. 18.83
C. 20.83
D. 17.83
E. 19.83
A flea collar for dogs contains an active ingredient that evaporates at a rate propor- tional to the amount still present. Half of the ingredient evaporates in the first 15 days af- ter the collar is removed from the protective packaging. If the collar becomes ineffective after 60% of the active ingredient has evaporated, how many days does the collar remain effective?