Yesterday, Grace drove 43 1/2 miles. She used 1 1/4 gallons of gasoline. What is the unit rate for miles per gallon?

explanation:

infrared radiation has wavelength in the range between 700 nm and 1 mm. lets' convert these values into scientific notation, keeping in mind that:

let's start from the lower value, we have:

(we moved the dot two places to the left, so we increased the exponent by 2 units, from -9 to -7)

the higher value is:

so, the range of wavelength of infrared radiation is:

shorter then the tree

so mark-up is 0.4 multiplied by 180 = 72