I do AOPS I am robot317

​there can be 5+4+3+2+1=15 ways to do it and
you can flip them 2 times to get 15*4=60

Answer=60

(B)452.39 since it is A=4πr^2 and r=6 so A=452.39

x=100 since CXF=100 degrees and by similar angles x=100 degrees

If I am not correct then it is:

We get that Y=75 because the triangle is isoceles and (180-30)/2=75 we make a new iscoeles triangle where that Y is an angle.We find out that the angle is 30 degrees by similar triangles and subtract 77.5-30 to get 47.5 then we do 47.5*2=95 and we finally do 180-95=75 to get X=75 so X+Y=75+75=150 so at last the answer is X+Y=150

We get that Y=75 because the triangle is isoceles and (180-30)/2=75 we make a new iscoeles triangle where that Y is an angle.We find out that the angle is 30 degrees by similar triangles and subtract 80-30 to get 50 then we do 50*2=100 and we finally do 180-100=80 to get X=80 so X+Y=80+75=155 so at last the answer is X+Y=155

you can't take a calculator everywhere so just figure out a trick it is fun 

I'm sure that Ziggy is right becuase that is what I did also

so we take the last digits of the number and multiply them to get 4*9*3*6 and that is 648 so we take that last number to get 8 and the last digit of the product of 684 * 59 * 413 * 76 is 8