If n arthimetic means are inserted between 6.2 and 19.4, the sum of the resulting term is 76.8 find 'n'

Find the center and the radius of the circle with the equation: x^2-2x+y^2+4y+1=0?

Jack did 3/5 of all problems on his weekend homework before sunday. on sunday he solved 1/3 of what was left and the last 4 problems. how many problems were assigned for the weekend?

The holiday party will cost $160 if 8 people attend.if there are 40 people who attend the party, how much will the holiday party cost