In how many ways can 4 people sit down in 6 seats in a row so that the leftmost and rightmost seat is empty

Ricardo ran the 400 meter race 3 times his fastest time was 54.3 seconds his slowest time was 56.1 seconds if his average time was 55.0 seconds what was his time for the third race

Find the values of y: 3y^3(y^2+ 2/3y)=0

Which of the following is equal to the square root of the cube root of 5 ? (1 point) 5 to the power of 1 over 3 5 to the power of 1 over 6 5 to the power of 2 over 3 5 to the power of 3 over 2