I might be bad at explaining or even wrong, but i tried. so here it goes.
2 is subtracted from a number (we'll put N for the missing number) and the difference is divided by 3. so i thought the difference was the final answer so i divided 30 by 3.
my equation came out to 2-n=30/3
so from there i did basic algebra.
i added the N to both sides so i came up with 2=30/3+N (so i wouldn't have a negative variable) and the divided 30/3 so then i had 2=90+N.
still with me? i hope so...
so then i subtracted 90 from both sides to get the variable alone and ended with -88=N.
so if you put N in you get 2-(-88)=30/3
you subtract 2 from -88 and get 90. so now you have 90/3 with equals 30.
Points J, K and M form a triangle.
In this triangle you are given the angles for JKM (50) and KJM (60)
The 3 inside angles of a triangle need to equal 180.
The third angle JMK would be 180 minus the two given angles:
JMK = 180 - 50 - 60 = 70
JMK = 70 degrees
a=180-142=38 degree
b= 180-38-88=54 degree
c=b (since the two lines are parallel to each other) therefore c=54 degree
This answer is the third choice, C