Please Help. Ellis spends $850 per month on fixed expenses. Ellis earns $20 per hour. How many hours does Ellis need to work each month to spend 50% of his/her income on fixed expenses?

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: