Question

A partially filled pool contains 600 gallons of water. A hose is turned on, and water flows into the pool at the rate of 8 gallons per minute. How many gallons of water will be in the pool after 70 minutes?

Answer 1

Hint:We need to use unitary method in this case. In unitary method if we know the price of a particular product we can find the price of a number of products by multiplication. Also we can find the price of a single product if we are given the price of a number of products with division.

Complete step by step solution:
Given:A partially filled pool contains = \[600\] gallons of water-----------equation (1)
Water flowing into the pool per minute= 8 gallons
i.e. In every minute the pool is filled with 8 gallons more water.
Applying unitary method.
Water filler in one minute \[ = {\text{ }}8\] gallons
Water filled in \[70\]minutes \[ = \]\[7 \times 8\]
                  \[ = 560\] gallons ------equation (2)
Total water in the pool after \[70\]minutes\[ = \] water
Already present in the field\[ + \] Water filled in \[70\] minutes---------equation(3)
Use values from (1) and (2) in (3)
We get,
Water in the pool after \[70\] minutes \[ = {\text{ }}600 + 560\
         \[ = 1160\] gallons


Note: In unitary method when we need to go from smaller to bigger figure we use multiplication.
But when we need to go from bigger to similar, then we will be using division.