You add the sides then multiply your answer with the sides.
The main reason was to prevent communism in Vietnam Also to Help reduce the french influence towards Vietnam. Hope this helps!
100 * (2/3) ~ 66.67
Round up, because you need a whole number which is at least 66.67
And your final answer is 67.
They basically got the power as easily as anyone can but they made it a point to keep the people thinking that they were doing right by them.