Pure acid is to be added to a 10% acid solution to obtain 90L of 19% solution. What amounts of each should be used? How many liters of 100% pure acid should be used to make the solution?

For what is the measure of the angle at the top of the shed? a. multiplication of areas b. squaring of areas c. addition of areas d. division of areas

Hi my sisters and brothers can tell me the answer because i don’t understand the question

During a bike challenge riders have to collect various colored ribbons each 1/2 mile they collect a red ribbon each eighth mile they collect a green ribbon and each quarter mile they collect a blue ribbion wich colors of ribion will be collected at the 3/4 markrer