we are given
The water level in Ricky lake changes at an average of -7/48 inch for 1 year
It means that
In 1 year , the water level changes at
and we have to find the water level change after 5 years
so, we can multiply both sides by 5
In 5*1 year , the water level changes at
In 5 years , the water level changes at
Hence,
the water level change after 5 years is ........Answer
