Answer:
D
Explanation:
To know which is most or least cost-effective, it's not enough to look at only the per day rate, or only the time to complete. You have to multiply them to get the total cost of the project.
![\left[\begin{array}{ccccc}&Cost\ per\ day\ (\$)&Time\ to\ complete\ (days)&Total\ cost\ (\$)\\Zoe&500&8&4000\\Greg&650&10&6500\\Orion&400&12&4800\\Jin&700&5&3500\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccccc%7D%26Cost%5C%20per%5C%20day%5C%20%28%5C%24%29%26Time%5C%20to%5C%20complete%5C%20%28days%29%26Total%5C%20cost%5C%20%28%5C%24%29%5C%5CZoe%26500%268%264000%5C%5CGreg%26650%2610%266500%5C%5COrion%26400%2612%264800%5C%5CJin%26700%265%263500%5Cend%7Barray%7D%5Cright%5D)
As you can see, Greg is the least cost-effective because he charges the most for the project.
Answer:
c
Explanation:
if someone is wrong that they can help with
5 is the correct one to choose for this
The first one is d or the 4th answer choice and the second one is false. Hope this helps!
Solution :
The nuclear reaction for boron is given as :

And the reaction for Cadmium is :
![$^{113}\textrm{Cd}_48 + ^{1}\textrm{n}_0 \rightarrow ^{114}\textrm{Cd}_48 + \gamma [5 \ \textrm{MeV}]$](https://tex.z-dn.net/?f=%24%5E%7B113%7D%5Ctextrm%7BCd%7D_48%20%2B%20%5E%7B1%7D%5Ctextrm%7Bn%7D_0%20%5Crightarrow%20%5E%7B114%7D%5Ctextrm%7BCd%7D_48%20%2B%20%5Cgamma%20%5B5%20%5C%20%5Ctextrm%7BMeV%7D%5D%24)
We know that it is easier that to shield or stop an alpha particle (i.e. He nucli) as they can be stopped or obstructed by only a few centimetres of the material. However, the gamma rays ( γ ) can penetrate through the material to a greater distance. Therefore, we can choose the first one.