In 1988 the population f Abra increased by 20% while the population of Cadabra decreased by 10% after which thw two populations were equal. What % of the original population of Cadabra was the orginal poplation of Abra?
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In 1988 the population f Abra increased by 20% while the population of Cadabra decreased by 10% after which thw two populations were equal. What % of the original population of Cadabra was the orginal poplation of Abra?
population of Abra P.A. = x + 20%x = x(1+20%)Quote:
Originally Posted by Rimas
population of Cadabra P.C.= y(1- 10%)
then they becom equal so
x= y (1- 10%)/(1+20%)=9y/12
Hello,Quote:
Originally Posted by Rimas
let A be the population of Abra and
let C be the population of Cadabra.
Then you can set up the equation:
$\displaystyle 120\% A= 90\% C \Longrightarrow \frac{A}{C}=\frac{90\%}{120\%}=\frac{3}{4}$
That means the population of A was 3/4 = 75% of C.
EB
