There lives a population of lemurs on an island which can either be healthy, be sick, or be dead. Each year, there is 0.2 probability that a healthy lemur gets sick and 0.1 probability that it dies; there is 0.3 probability that a sick lemur recovers and becomes healthy and 0.6 probability that it dies (and dead lemurs stay dead forever). a. An ecologist visits the island and observes that in 1990 there are 1000 healthy lemurs. Of that population, how many will still be alive in 5 years, in expectation? b. If the ecologist visits the island again in 1993, how many of the lemurs she observes from the original population will not have experienced sickness at any time since she last saw them?

step-by-step explanation:

what grade level is this? need to know so i can look in my old textbooks!

the answer is 1030 it's very simple math.

fabric (square meters)                   cloaks

7                                                           21

4/3                                                         4

step-by-step explanation:

we are told that harry needs 2 square meters of fabric for every 6 wizard cloaks he makes.

1. first of all we will find how many cloaks can be made from 1 square meter of fabric by dividing 6 by 2.

we can see that 3 cloaks can be made from 1 square meter of fabric. now we will multiply 3 by 7 to find number of cloaks made from 7 square meters of fabric.

therefore, harry will make 21 cloaks from 7 square meters of fabric.

2. let us find how many square meters of fabric will be needed to make 4 cloaks.

first of all we will find fabric needed for 1 cloak by dividing 2 by 6.

we can see that fabric needed for 1 cloak is   square meter. now we will multiply   by 4 to find fabric needed for 4 cloaks.