A shop sells three brands of light bulb. Brand A bulbs last for 760 days each. Brand B bulbs last for 690 days each. Brand C bulbs last for 720 days each. Calculate the cost of 1 day's use for 1 bulb in each brand. Give your answers in pence to 3 dp.

According to a study conducted in 2015, 18% of shoppers said that they prefer to buy generic instead of name-brand products. suppose that in a recent sample of 1500 shoppers, 315 stated that they prefer to buy generic instead of name-brand products. at a 5% significance level, can you conclude that the proportion of all shoppers who currently prefer to buy generic instead of name-brand products is higher than .18? use both the p-value and the critical-value approaches.