Subject: General Aptitude · Chapter: Ratio and Proportion · Exam: · Marks: · Difficulty:
An employer reduces the number of his employees in the ratio of 9 : 8 and increases their wages in the ratio 14 : 15. The difference in the amount of the total salary bill which was originally ₹ 1890 after the above two changes will be
(a)₹ 90
(b)₹ 100
(c)₹ 110
(d)₹ 120
Answer
Answer (as printed): A
Explanation
Let the initial number of employees be $9x$ and their wages be ₹$14y$. Then, reduced number of employees $= 8x$. And, increased wages $= ₹15y$. Original wage bill $= ₹(9x \times 14y) = ₹(126xy)$. $$126xy = 1890 \Rightarrow xy = \frac{1890}{126} = 15.$$ New wage bill $= ₹(8x \times 15y) = ₹(120xy) = ₹(120 \times 15) = ₹1800$. Required difference $= ₹(1890-1800) = ₹90$.
Explanation as extracted from the printed page; notation may be imperfect.