Mass box C is 10+5. (So C is 15)
But if C was 30, how many times could you put B (5) into it?
30/5 = 6
You would need 6 boxes of B to make 30 grams of C.
At 12 mph, how long does it take to go 13.1 miles?
We know that distance = rate * time
So we know that 13.1 = 12 * time
We can now see that time = 13.1/12 = 1.092 (hours)
That's approximately 1 hour and .092*60=5.52 minutes.
The answer to this question is: B) 3+
First, we will get the "n", the number of half lives, it is the elapsed time over the half life. In the problem, the time is measured in days, so we have
6/2 = 3
to get the ending amount of radioactive sample, we have
32g x (1/2)³ = 4 grams of radioactive sample ⇒ the amount left after 6 days