A species of phytoplankton measures about 2 × 10–6 in. A grain of sand measures about 1 × 10–4 in. About how many times longer is the grain of sand than the phytoplankton?

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.

Ze trinomial x2 + bx – c has factors of (x + m)(x – n), where m, n, and b are positive. what is ze relationship between the values of m and n? explain how you got ze answer

42. if 20 men can eat 200 kg of wheat in 40 days, then 10 men can eat 300 kg of wheat in how many days? a) 120 days b) 60 days c) 80 days d) none of these