Question

The efficiency of a machine is directly proportional to the number of units produced. If the efficiency of the machine is 125 % when 25 units are produced, then find the efficiency of the machine when 10 units are produced .

• A. 100 %
• B. 150 %
• C. 75 %
• D. 50 %

Answer 1

The correct option is D 50 %

Given, the efficiency of a machine (E) is directly proportional to number of units produced(N).
$\Rightarrow E\propto N$
Let the constant of variation be k.
$\Rightarrow E=kN$
Given, at E = 125% , N = 25.
$So,k=\frac{E}{N}=\frac{125}{25}=5.$
Hence, the the efficiency of the machine when 10 units sre produced (i.e N = 10) = kN = (5)(10) = 50 %.