Plz help me with all 3 answers

answer: it's a

step-by-step explanation:

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:

$119.20

step-by-step explanation:

$372.50 - 60% off is $149. $149-20% off is $119.20