ANSWER
15 shots
EXPLANATION
Klay has made 1/3 of his attempted shots.
Let the number of attempted shots be x.
This means that he has made:
1/3 * x = x/3
If he makes his next 5 shots, his shooting percentage will increase to 50%. In other words, he will have made half hsi attempted shots.
Adding 5 shots to the shots he already attempted before is:
x + 5
So, now, he would have made:
1/2 * (x + 5)
This is the same as adding the number of shots he had made before to the number of shots he has made now. That is:
[tex]\begin{gathered} \frac{1}{2}(x\text{ + 5) = 5 + }\frac{1}{3}x \\ \text{Expand and collect like terms:} \\ \frac{1}{2}x\text{ + }\frac{5}{2}\text{ = 5 + }\frac{1}{3}x \\ \frac{1}{2}x\text{ - }\frac{1}{3}x\text{ = 5 - }\frac{5}{2} \\ \Rightarrow\text{ }\frac{1}{6}x\text{ = }\frac{5}{2} \\ \text{Multiply both sides by 6:} \\ x\text{ = }\frac{5}{2}\cdot\text{ 6} \\ x\text{ = 15} \end{gathered}[/tex]This means that he had attempted 15 shots when he was at 1/3 success rate.