In an 80/20 mortgage, what is the second mortgage used for?

My math teacher told my class to "steal" a 6th grade fraction word problem from the internet, word problems? : -p requirements: only a 1 step word problem. needs to be complex.

If u good at math hit me up on insta or sum @basic_jaiden or @ and

Which has the greater energy, light of wavelength 519 nm or light with a frequency of 5.42 x 10^8 sec^-1?