Question:
The mean of 1, 3, 4, 5, 7, 4 is m. The numbers 3, 2, 2, 4, 3, 3, p have mean m − 1 and median q. Then, p + q =
(a) 4
(b) 5
(c) 6
(d) 7
Solution:
$1,3,4,5,7,4$
Mean $=\frac{1+3+4+5+7+4}{6}$
$=\frac{24}{6}$
$=4$
$M=4$
Consider the numbers 3, 2, 2, 4, 3, 3, p.
Mean $=\frac{3+2+3+4+3+3+p}{7}$
$\Rightarrow 7 \times(4-1)=17+p$
$\Rightarrow 21=17+p$
$\Rightarrow p=4$
Arranging the numbers 3, 2, 2, 4, 3, 3, 4 in ascending order, we have
2, 2, 3, 3, 3, 4, 4
Median $=\left(\frac{n+1}{2}\right)^{\text {th }}$ term
$q=\left(\frac{7+1}{2}\right)^{\text {th }}$ term
$=\left(\frac{8}{2}\right)^{\text {th }}$ term
$=4^{\text {th }}$ term
$\therefore q=3$
So,
$p+q=4+3$
$=7$
Hence, the correct option is (d).