sales advertised in its local n? Seventy percent of all Big Burger chain stores decided to advertise in their local newspapers. Of those chain stores that advertised in their local newspapers, 60% had an increase in sales. Of those chain stores that did not advertise in their local newspapers, 25% had an increase in sales.

a) What is the probability that a randomly selected store with an increase in sales advertised in its local newspaper?

I got 42% for a) but i am not sure if this is correct. My friend thinks it is 70%. Thanks for the help!