22 Simon, Cheryl and Dannii are all going by
train to London to watch a singing
competition.
Cheryl gets the 2:15 pm train.
Simon's train journey takes 50% longer than
Dannii's.
Simon catches the 3:00 train.
Dannii leaves 20 minutes after Cheryl and
arrives at 3:25 pm.
When will Simon arrive?
(1 Point)​

The rate of decay of a radioactive substance depends upon the amount present initially. the mass y (mg) of the radioactive substance cobalt-60 present in a sample at time t (years) is represented by the exponential equation y=50e −0.1315 t . answer the following questions in complete sentences. 1. how does the exponential equation above compare to the equation for simple interest that is compounded continuously? explain the similarities. 2. what is the initial amount of cobalt-60 in the sample? 2. how much cobalt-60 is left after 8.4 years? show your work. 3. what would be the y-intercept of the graph? what does it represent? 4. after how many years will the amount of cobalt-60 left be 6.25 mg? explain what happens to the cobalt-60 after 50 years? 5. discuss some “real-world” examples and uses of cobalt-60

12 3 4 5 6 7 8 9 10time remaining01: 24: 54which graph represents this system? y=1/2x + 3 y= 3/2x -1

Find the root(s) of f (x) = (x- 6)2(x + 2)2.