You solve this by using google.com or YouTube.com
Or just pay attention in class to get this.
1.) First plug in the values for m and A:

--> 
Isolate b: 
b = 1999
So your answer is the first option.
2.) Admission costs $5.25, so even if you don't go on any rides, you will still have to pay $5.25. This means that for this problem, 5.25 will be the b value. If each ride costs $2.50, then this means it is $2.50x for the cost of x rides. The total cost will then be
.
Remember
(ab)/(cd)=(a/c)(b/d)
and

1kg=1000g=1*10^3g
hmm, I estimate, 4 of them
x=number of attoms
mass of 1 times x=1*10^3
3.95*10^-22 times x=1*10^3
divide both sides by 3.95*10^-22
x=

=

=

a million has 9 zeroes
so 24 zeroes is alot that is a <span>septillion, so there are 2.5316 septillion uranium atoms in 1kg
a. 4
b. underestimate
</span>
Answer:
3 1/2
Step-by-step explanation: