25 pts and a mark a chemical company makes two brands of antifreeze. the first brand is 65 % pure antifreeze, and the second brand is 90 % pure antifreeze. in order to obtain 30 gallons of a mixture that contains 80 % pure antifreeze, how many gallons of each brand of antifreeze must be used?

With these 5 geometry questions! pls 1.)quadrilateral abcd is inscribed in this circle.what is the measure of ∠a ? enter your answer in the box.°2.)quadrilateral abcd is inscribed in a circle.what is the measure of angle a? enter your answer in the box.m∠a= 3.)quadrilateral abcd is inscribed in this circle.what is the measure of angle b? enter your answer in the box.m∠b= °4.)quadrilateral abcd is inscribed in this circle.what is the measure of angle a? enter your answer in the box.°5.) quadrilateral abcd is inscribed in this circle.what is the measure of angle c? enter your answer in the box.°