The formula f equals c over lambda, where f = frequency, c = wave speed, and λ = wavelength, is used to calculate frequency. Solve this formula for c.

Abby is preparing fruit punch for her party. she starts with a bowl filled with liquid that has 1/2 fruit juice and 1/2 sprite, but she decides it's too fruity. so she pours out 1/4 of the liquid, and then fills the bowl up again with sprite. what fraction of the punch is now sprite?

Prove that the value of the expression 7^8–7^7+7^6 is divisible by 43.

2.5 milligrams is equivalent to how many grams