The answer is F.30 Explanation: If we do guess and check, if we multiply the ratios by 10, it would be 30:40:50, which doesn’t add up to 180 degrees. if we multiply the ratios by 20, It would be 60:80:100, which also doesn’t add up to 180 degrees. How about we multiply the ratios by 15? It would be 45:60:75, which does add up to 180! The difference between x and z is 30, so the answer is F.30