How do you find the new amount given 80 members decreased by 65%?

2 Answers
smendyka
Aug 24, 2017

See a solution process below:

Explanation:

We can write an equation for this problem as:

#n = m + (m * r)#

Where:

#n# is the new number of members. What we are solving for.

#m# is the original number of members. 80 for this problem.

#r# is the rate of change in membership. -65% for this problem because there was a decrease in the number of members. "Percent" or "%" means "out of 100" or "per 100", Therefore -65% can be written as #-65/100#.

Substituting and calculating #n# gives:

#n = 80 + (80 * -65/100)#

#n = 80 + (-5200/100)#

#n = 80 + (-52)#

#n = 80 - 52#

#n = 28#

There are now 28 members.

EZ as pi
Aug 24, 2017

#28# members

Explanation:

If there is a decrease of #65%# , it means that #100%-65% = 35%# of the members are left.

So we just need to find #35%# of 80.

#35/100 xx 80 = 28# members.

The other way is to find the actual decrease, which is:

#65/100 xx 80 = 52# members

#80-52 = 28# members remain.

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