Question

The average of $11$ results is $50$. If the average of the first six results is $49$ and that of the last six is $52$, then the sixth result is _____________.

• A. $53$
• B. $54$
• C. $55$
• D. $56$

Answer 1

Answer: (D)

$56$

Mean of $11$ results $=50$

$\Rightarrow$ Sum of these $11$ results $=550$

Sum of first six results $=49\times 6=294$

Sum of last six results $=52\times 6=312$

$\therefore$ Sixth result $=$ Sum of first six results $+$ Sum of last six results $-$ Sum of all $1$ results

$=294+312-550=56$