In a village of 100 households, 75 have at least one DVD player, 80 have at least one cell phone, and 55 have at least one MP3 player. If x and y are respectively the greatest and lowest possible number of households that have all three of these devices, x - y is:
বিকল্পসমূহ (নিজের উত্তর যাচাই করতে ক্লিক করুন):
সঠিক উত্তর
2 (45)
বিস্তারিত ব্যাখ্যা ও বিশ্লেষণ:
Solution:
The obvious maximum that have all 3 is 55, because you are limited by the smallest number.
The minimum is simply the sum of the max of each people who dont have the product, so:
100 - 80 = 20 don't have Cell
100 - 75 = 25 don't have DVD and
100 - 55 = 45 don't have MP3
So a total of 20 + 25 + 45 = 90 combined who might not have some combination of the 3 products.
So subtract that from 100, to give you the minimum of the people who could have all 3 and you get
100 - 90 = 10.
55 - 10 = 45
