๐๐ผIn 2016 the average waiting time for an operation was 15 days. By 2020 it had been reduced to 15 days. Calculate the percentage decrease.

๐๐ผAt a concert there are men, women and children, such that men and women are in the ratio 5:7 and children and women are in the ratio 2:3. If there are 800 people at the concert, then how many women are there?

๐๐ผIf a CD costs ยฃ6.79, calculate without a calculator the cost of 5 CDs.

๐๐ผShow the following data on a Venn diagram: ฮพ = { positive integers under 30}, A = { primes under 30}, B = { 2, 6, 7, 8, 9, 11, 15, 18, 21, 27}

๐๐ผUse the Venn diagram to calculate P(AโฉB)