<span><span>The probability of all calculators having no defects is 16.8%. The probability of at least one defect is the complement of that probability. ie an 83.2% probability of at least one defect.</span><span> </span></span>
we know that 60% of x is 120. we can rewrite this to .6x = 120, to get x we divide both sides by .6, so x = 200. now 120 + 30 = 150. then we divide 150 out of 200 which is .75 it 75%
