Question

Arnav scored 63 marks in English, 57 in Hindi, 82 in Mathematics, 55 in Social Science and 𝑥 in Science. If the average he scored is 70, find the average of the best of four scores.

Answer 1

$Average=\frac{Sumofobservation}{Totalnumberofobservation}$
$Sumofobservation=63+57+82+55+x=257+x$
$Totalno.ofobservations=5\left(given\right)$
So,
$Average=\frac{257+x}{5}$
$70=\frac{257+x}{5}$
$70\times 5=257+x$
$350=257+x$
⇒ $x=93$

Thus, he scored $93$ in science.
So,
Arnav's best scores among his 5 subjects are : $93,82,63$ and $57$.
$Average=\frac{93+82+63+57}{4}$
$Average=\frac{295}{4}=73.75$
Hence, the average of the best of four scores is 73.75.