2019 WVPS CA1 Paper 2
Farah had $180 more than Tim. After giving To of her money to Tim Tim ha
$84 more than her. How much money did Farah have left?

i think the amount would be $140.62

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: