Can someone help me please? (T^T)

This doesn’t make sense to me it’s supposed to be lcm ( least common multiple )

1. are the triangles similar and if so why? what is the value of x? show your work.

Assume that the weights of quarters are normally distributed with a mean of 5.67 g and a standard deviation 0.070 g. a vending machine will only accept coins weighing between 5.48 g and 5.82 g. what percentage of legal quarters will be rejected? round your answer to two decimal places.