Subject: General Aptitude · Chapter: Average · Exam: · Marks: · Difficulty:
The average of 7 consecutive numbers is 20. The largest of these numbers is
(a)20
(b)22
(c)23
(d)24
Answer
Answer (as printed): C
Explanation
Let the numbers be $x, x+1, x+2, x+3, x+4, x+5$ and $x+6$. Then, $$\frac{x+(x+1)+(x+2)+(x+3)+(x+4)+(x+5)+(x+6)}{7}=20$$ or $7 x+21=140$ or $7 x=119$ or $x=17$. ∴ Largest number $=x+6=23$.
Explanation as extracted from the printed page; notation may be imperfect.