# How to find the percentage decrease necessary to restore a quantity to its original value?

If the original value has been increased by 18% what percentage decrease is necessary to restore a quantity to its original value?

also

the profit was \$3650 last year, but this year it decreased by 42%. what percentage must the profit increase next year to restore it to its original value?

Relevance
• 7 years ago

Hi,

If the original value has been increased by 18% what percentage decrease is necessary to restore a quantity to its original value?

If something is now 118% of its former value, the former value is 100/118 of its current value, so it needs to be reduced by 18/118 or by 15.254% of its current value. <==ANSWER

The profit was \$3650 last year, but this year it decreased by 42%. what percentage must the profit increase next year to restore it to its original value?

If the profit decreased by 42%, it is currently 58% of its current value. To return to its former amount it must become 100/58 or 172.41% of its current amount. This is an increase of 72.41% over its current value. <==ANSWER

I hope that helps!! :-)

• sward
Lv 4
3 years ago

artwork in fractions, no longer probabilities. V + 10% = V + 0.1V = (a million + 0.a million)V = a million.1V to shrink all the way down to V, a million.a million V x r = V r = V / a million.1V r = a million/a million.a million = 0.909, or 9.09% W - 80% = W - 0.8W = (a million - 0.8)W = 0.2W 0.2W x r = W r = W / 0.2W r = a million/0.2 = 5, it is 500%