Question

The average (arithmetic mean) of $t$ and $y$ is $15$, and the average of $w$ and $x$ is $15$. What is the average of $t,w,x$ and $y$?

• A. $7.5$
• B. $15$
• C. $22.5$
• D. $30$

Answer 1

The correct option is B $15$

Given, Average of $t$ and $y$ $=$ $15$

$\Rightarrow \frac{t+y}{2}$ $=$ $15$

$\Rightarrow t$ $+$ $y$ $=$ $15$ $\times$ $2$

$\Rightarrow t$ $+$ $y$ $=$ $30$

Average of$w$ and $x$ $=$ $15$

$\Rightarrow \frac{w+x}{2}$ $=$ $15$

$\to w$ $+$ $x$ $=$ $15$ $\times$ $2$

$\Rightarrow w$ $+$ $x$ $=$ $30$

Now, average of $t$, $y$, $w$ and $x$ $=$ $\frac{(t+y+w+x)}{4}$

$=$ $\frac{(t+y)+(w+x)}{4}$

$=$ $\frac{30+30}{4}$

$=$ $\frac{60}{4}$

$=$ $15$

Therefore, average of $t$, $y$, $w$ and $x$ is ${}^{\prime }{15}^{\prime }$.