Please help with Stats Question.

Can use any sample size calculator or method to reach solution, but please show and explain how!

1) For a subset of patients it has been shown that a certain type of skin lesion will develop into cancer in 34% of patients if left untreated. There is a drug on the market that currently reduces this event rate to 28%.A pharmaceutical company is developing a new drug to treat these lesions but this would be worthwhile only if the new drug can reduce this further to 23%.In planning for a randomized clinical trial, how many evaluable participants are needed to have 80% power to detect a difference of 28% and 23% in the progression to cancer between the current and new drug?

2) Researchers are interested in reaction times under two conditions.A prior study reported reaction times of 12 minutes and 15 minutes for the two conditions with a common standard deviation of 10. How many experimental units should be used in the study to have 80% power to detect a similar difference? Assume a 5% level of significance.

3) How does the effect size affects the power of a test? Provide an example along with your explanation.