Answer:
63
Step-by-step explanation:
Find 10% of 90 which is 9 then multiply by 3 to get 30%. You get 27 them you ssubtract that from 90
Since they all begin with 2, you need to look for the biggest number after the decimal point, since it's 4 then 2.4 is the biggest number
![4^{x} = 64](https://tex.z-dn.net/?f=%204%5E%7Bx%7D%20%3D%2064)
By taking <span>logarithmic of base 10
∴ </span><span>
![log 4^{x} = log 64](https://tex.z-dn.net/?f=%20log%204%5E%7Bx%7D%20%3D%20log%2064)
∴ x log 4 = log 64
∴
![x = \frac{log \ 64}{log \ 4}](https://tex.z-dn.net/?f=x%20%3D%20%20%5Cfrac%7Blog%20%5C%2064%7D%7Blog%20%5C%204%7D%20)
∴ The correct choice is
</span><span>x = log base 10 of 64, all over log base 10 of 4</span>