Hi, thank you for posting your question here at Brainly.
To find the velocity of light or any electromagnetic wave, we use the equation: v = wavelength * frequency. Substituting,
v = 0.5 m * 930 1/s
v = 465 m/s
If there is 10% of $18 = 18 x 0.9 (1 - 0.1) = $16.20
Therefore the pie costs $16.20
He is saving 18 - 16.20 = $1.80
The answer your looking for is 7.5ft by 1.5ft hope this helped have a nice day :)
So what you do is you want to multiply
3.8 × 50=190km