The average age of A, B and C is 30 years. If the difference between B’s age and A’s age is the same as the difference between C’s age and B’s age. If D is 40 years older than B then what is the sum of the age of B and D?
বিকল্পসমূহ (নিজের উত্তর যাচাই করতে ক্লিক করুন):
সঠিক উত্তর
3 (100 years)
বিস্তারিত ব্যাখ্যা ও বিশ্লেষণ:
A + B + C = 30×3 = 90 yrs ...... (1)
ATQ,
B - A = C - B
Or, A+C = 2B
From (1),
B + 2B = 90
Or, B = 30
∴ D = B + 40 = 30 + 40 = 70
So, B + D = 30+70 = 100 yrs
