2 Here are seven counters. Each counter has a number on it.
2
5
5
5
Ali puts the seven counters in a bag.
He takes, at random, a counter from the bag and does not replace the counter
He then takes, at random, a second counter from the bag.
Calculate the probability that
the number on the scoond counter is 2 more than the number on the first counter,
(11) the number on the second counter is 1 more than the number online first counter.

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

20 solve 2(4 x + 3) < 5 x + 21. a) { x | x < 9} b) { x | x > -5} c) { x | x > -9} d) { x | x < 5}

Hundred and tens tables to make 430 in five different ways