Of four numbers whose average is 60, the first is one-fourth of the sum of the last three. The first number is –
A. 15 B. 42 C. 45 D. 48 Answer: Option DShow Answer
Solution(By Apex Team)
Let the four numbers be a, b, c and d respectively
Then,
$\begin{array}{l}\text{⇒ a =}\frac{1}{4}\text{(b + c + d)}\\
\text{⇒ b + c + d = 4a}\\
\text{Also,}\\
\text{a + b + c + d = 60 × 4 = 240}\\
\text{⇒ a + 4a = 240}\\
\text{⇒ 5a = 240}\\
\text{⇒ a = 48}\\
\text{Hence, first number = 48}\end{array}$
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