1) If you want to split something ina 2:5 ratio, you must break it into 2+5=7 pieces. Then, you assign 2 of these 7 pieces to one person and the 5 remaining pieces to the other, and they'll have 2/7 and 5/7 of the total. for a ratio of 2:5, as required.
So, kindonoghwa gets 2/7 of 200000000, which is approximately 57142857.14.
2) We have
[tex]4\log_2(x)=4[/tex]
Divide both sides by 4:
[tex]\log_2(x)=1[/tex]
This is equivalent to
[tex]2^{\log_2(x)}=2^1 \iff x=2[/tex]
