The depth of a lake in Greenpoint changes over time due to rainfall and evaporation. This year it was 539 feet, which is 10% deeper than it was last year. What was last year's depth

485.1 feets

Step-by-step explanation:

Given that:

Depth of Lake changes over time due to Rainfall and evaporation :

Depth this year = 539 feets

Depth this year is 10%deeper than last year's depth

Depth last year will be ;

Since, this year's depth is greater Than last year :

depth last year equals ; (depth this year - 10% of depth this year)

Depth last year:

539 - (0.1 *539)

539 - 53.9

= 485.1 feets

for ex: the reciprocal of 3/4 is 4/3. it is the opposite.

reciprocal definition:

a mathematical expression or function so related to another that their product is one; the quantity obtained by dividing the number one by a given quantity.