Iodine-125 has a half-life of about 60 days.

how many milligrams of a 1000mg sample will remain after 240 days?

62.5 mg

Step-by-step explanation:

Half-life of Iodine-125 is 60 days

It means the sample loses weight twice in every 60 days

This is a GP with first term of 1000 mg, common ratio of 1/2 and number of  terms:

Last term is the remaining sample after 240 days:

Answer is: 62.5 mg of Iodine-125 remains after 240 days

the slope of the line is 60

one point on the line is (40,10)

step-by-step explanation:

in the equation outside the parenthesis the equation always tells you the slope. in this case it is 60.

in the parenthesis is also says 40 which is x because it is near the x and 10 is y because it is near y.