Question

If the population of a country increased by 100%.And the new population is 360.find the old population

Answer 1

Answer:-

$\boxed{\red{\sf Initial \: population\:of\:country\:was\:180.}}$

Note:-

• Let us say if the population of a country increases by x% . And if the initial population was y . Then the new population will be ;

$\purple{\boxed{\sf\gray{ \bigg\lgroup\dfrac{100+x}{100}\bigg\rgroup y }}}$

• Let us say if the population of a country dereases by x% . And if the initial population was y . Then the new population will be ;

$\purple{\boxed{\sf\gray{ \bigg\lgroup\dfrac{100-x}{100}\bigg\rgroup y }}}$

Explanation :-

Given that the , population of a country increased by 100%.And the new population is 360 . So ,let us take

• initial population be p .

Now ,the population is increased by 100% . So , the increased number of people will be , 100% of 360 = 360 .

$\sf=> New\: population=\cancel{\dfrac{100}{100}}\times p + p \\\\=>\sf 360 = x + x =360\\\\=>\sf 2x = 360 \\\\=>\sf x =\frac{360}{2}\\\\\boxed{=>\bf x = 180 }$

Hence the Original population was 180 .