Mrs. hara want to purchase blue light blocking glasses for her family. company 1 sells the glasses for $40 each, and company 2 sells the same glasses at 4 for $140. how much will Mrs. hara save, per pair of glasses, if she uses company 2?

Answer 1

If Company 1 sells the glasses for $40 each, and Company 2 sells the same glasses at 4 for $140, then the price per pair of glasses at Company 2 would be $140/4 = $<<140/4=35>>35.
Therefore, Mrs. hara would save $40 - $35 = $<<40-35=5>>5 per pair of glasses if she uses Company 2. Answer: \boxed{5}.