Question

The number of minutes needed to solve an exercise set of variation problems varies directly as the number of problems and inversely as the number of people working on the solutions. It takes $4$ people $36$ minutes to solve $18$ problems. How many minutes will it take $6$ people to solve $42$ problems.

• A. $54$ minutes
• B. $56$ minutes
• C. $60$ minutes
• D. None of these

Answer 1

The correct option is B $56$ minutes

Let the given Function be represented as

$Minutes=k(\frac{NumberOfProblems}{NumberOfPeople})$

Let us find the Value of $k$

$\Rightarrow 36=k\frac{18}{4}$

$\Rightarrow k=8$

Now Let us use the Above Formula for $problem=42$ and $people=6$

$Minutes=8\times \frac{42}{6}$

$Minutes=8\times 7$

$Minutes=56$

Therefore Answer is $\left(B\right)$