2 Nik owns a stationery shop. She bought 72 pencils for a total cost of £4.68

Nik sells all 72 pencils for 15p each.

Work out Nik's percentage profit.

Give your answer correct to 1 decimal place.

20 ! need which shows a difference of squares? 10y^2-4x^2 16y^2-x^2 8x^2-40x+25 64x^2-48x+9

Find the roots of the polynomial function f(x) = x^3 + 2x^2 + x

Ur environment is very sensitive to the amount of ozone in the upper atmosphere. the level of ozone normally found is 4.04.0 parts/million (ppm). a researcher believes that the current ozone level is not at a normal level. the mean of 2525 samples is 4.44.4 ppm with a standard deviation of 0.80.8. assume the population is normally distributed. a level of significance of 0.020.02 will be used. make the decision to reject or fail to reject the null hypothesis. answer tables