Question

A family used 9.8 gallons of gasoline to drive 275.5 miles.To determine how far they drove using one gallon of gasoline can they use an estimate or is an exact answer required? Explain

Answer 1

Given: 9.8 gallons of gasoline is used to drive 275.5 miles

To find: Number of miles that can be covered using one gallon

Solution:

Here we have to use cross multiplication method,

If 9.8 gallons is for 275.5 miles then for 1 gallon it will be,

$\Rightarrow 9.8 \text{ gallons }\rightarrow275.5 \text{ miles }\\\\\therefore 1 \text{ gallon }\rightarrow\frac{275.5\times1}{9.8}\text { miles }\rightarrow 28.11 \text{ miles }$

Here, the miles that can be covered using one gallon is 28.1122... miles. The decimal value goes on and does not end. So, to represent the the number of miles covered using one gallon gasoline, we can use the estimated decimal which is 28.11 miles.

Cross multiplications steps: (To find Single Variable)

1. Multiply the numerator of the left-hand fraction by the denominator of the right-hand fraction.

2. Multiply the numerator of the right-hand fraction by the denominator of the left-hand fraction.

3. Set the two products equal to each other.

4. Solve for the variable.