You have 72 grams of a radioactive kind of actinium. If its half-life is 6 hours, how much will be left after 12 hours

There will be 18 grams left after 12 hours.

Step-by-step explanation:

Half-life is the amount of time it take for a cell to turn from one condition to another.

To find the amount of grams for the first 6 hours.

72 ÷ 2= 36

Now, since 6 x 2 = 12, we need to divide 36 by 2 to find the next half-life.

36 ÷ 2 = 18

Therefore, there will be 18 grams left after 12 hours.

Hope this helps! :D

option (b) is correct

step-by-step explanation:

to find the solution of this system, we need to convert it into reduced row-echelon form. we have,

after applying row operations r2 -> r2/2 and r3 -> r3/3, we get,

= 5

step-by-step explanation:

to find the 15th term substitute n = 15 into the nth term formula

= (- 3 × 15 ) + 50 = - 45 + 50 = 5