2x – 3y = 17
–3x + y = –1
solve by elimination

You were told that the amount of time lapsed between consecutive trades on the new york stock exchange followed a normal distribution with a mean of 15 seconds. you were also told that the probability that the time lapsed between two consecutive trades to fall between 16 to 17 seconds was 13%. the probability that the time lapsed between two consecutive trades would fall below 13 seconds was 7%. what is the probability that the time lapsed between two consecutive trades will be between 14 and 15 seconds?

Asap! i'm not good math and i'm lost.

Given: circle o, cd is diameter, chord ab || cd. arc ab = 74°, find arc ca.