#Case 1
set.seed(100)
pvals = replicate(20, {
  cases = rnorm(10,30,2)
  controls = rnorm(10,30,2)
  t.test(cases,controls)$p.val
})
plessthan = replicate(1000, sum(pvals < 0.05))
table(plessthan)

#Case 2
set.seed(100)
B = 1000
plessthan = replicate(B,{
  pvals = replicate(20,{
    cases = rnorm(10,30,2)
    controls = rnorm(10,30,2)
    t.test(cases,controls)$p.value
  })
  sum(pvals<=0.05)
})
table(plessthan)