How old were the twins who played in the recital?

Yo need asap pls ! markin da brainiest too !

The weekly amount spent by a company for travel has an approximately normal distribution with mean = $550 and standard deviation = $40. a) what is the probability that the actual weekly expense will exceed $570 for more than 20 weeks during the next year? (note: one year = 52 weeks) b) what is the probability that actual weekly expenses exceed $580 for 10 or more, but 16 or fewer weeks during the next year?

An angle bisector ac divides a trapezoid abcd into two similar triangles ? abc and ? acd. find the perimeter of this trapezoid if the leg ab=9 cm and the leg cd=12 cm.