Lisa swam 6 times as many laps as Amanda , Brynne swam 15 more laps than Amanda, If Lisa and Brynne swam the same amount of laps, how many laps did Amanda swim?

If a || b and e || f , what if the value of y ?

Last month, a 770 g box of cereal was sold at a grocery store for $3.10. however, this month, the cereal manufacturer launched the same cereal in a 640 g box, which is being sold at $2.50. what is the percent change in the unit price?

Out of $20$ creepy-crawly creatures in a room, $80\%$ are flies and $20\%$ are spiders. if $s\%$ of the total legs belong to spiders, what is $s$?