A tank can be emptied by one pipe in 40 minutes and by another in 30 minutes. If the tank is 7/8 full, how long will it take to empty it when both pipes are open? (15 min)

Ican figure out 20 shares multiply by $117.98 =2359.6920 shares multiply by $124.32=2486.40then take 40 shares multiply by $128.48=5139.20after that i'm lost any be greatly appreciated.

The angle of a triangle are given as 6x,(x-3), and (3x+7). find x then find the measures of the angles

Two streets intersect at a 30- degree angle. at the intersection, the are four crosswalks formed that are the same length. what type of quadrilateral is formed by the crosswalks?