A student club has eighty members. One of its rules is that sixty-five percent of
members must be present to conduct a voting session. Determine how many members must be present
to conduct a voting session.
So there are eighty members and sixty-five percent of them need to be present in
order to conduct a voting session. So this question is asking what is sixty-five percent of
eighty? Now in order to calculate the percentage of a number, we do that percentage over a
hundred times the number. So that’s sixty-five over a hundred, sixty-five percent, times you can read
that for of eighty, the number that we’re trying to find the percentage of.
Now this is a fraction calculation. So just to make it nice and simple, I’m gonna
put eighty as eighty over one; eighty over one is the same as eighty. But when it’s in fraction
form, it enables us to look at this fraction calculation more easily. Now I can divide the top and the bottom by ten. Tens go into a hundred, ten times.
And tens go into eighty, eight times. Now looking at the sixty-five and the tenth, they’re both
divisible by five.
Five is going to ten two times and five is going to sixty-five thirteen times. Now I
can start doing more canceling: twos and eights. So two is going to two once; two is going into eight four
times. So this calculation becomes thirteen times four. Well to multiply something by four, I can just multiply it by two and then multiply it
by two again. So thirteen times two is twenty-six and twenty-six times two is equal to
fifty-two. So the answer is that at least fifty-two members have to be present in order to
conduct a voting session.