Question

Ariana starts with 100 milligrams of a radioactive substance. The amount of the substance decreases by 20% each week for a number of weeks, w. The expression 100(1−0. 2)w finds the amount of radioactive substance remaining after w weeks. Which statement about this expression is true?.

Answer 1

The required expression is 100 - 0.2w

Step-by-step explanation:Given,Amount of radioactive substance = 100 mgThe substance decreases by 20% each week.To find the remaining amount of the in w weeks.Now,Each week 20% = 0.2 of the substance will be decreased.So, in w weeks 0.2×w of the the substance will be decreased.Hence,The remaining substance = 100 - 0.2w