Seriously need on these two: (1. cylinder a has a radius of 1 m and height of 4m cylinder b has a radius of 1 m and height of 8m what is the ratio of the volume of cylinder a to the volume of cylinder ba. 1: 2b. 2: 1c. 1: 1d. 1: 4 2. what is the surface area of a conical grain storage tank that has a height of 42 meters and a diameter of 20 meters? round your answer to the nearest square meter. a. 3,028m^2b.3971m^2c.1,357m^2 d. 1,671m^2

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? a) it is the difference between the initial amount and the percent decrease. b) it is the difference between the initial amount and the decay factor after w weeks. c) it is the initial amount raised to the decay factor after w weeks. d) it is the product of the initial amount and the decay factor after w weeks.