Subject: General Aptitude · Chapter: Time and Work · Exam: 2003 · Marks: · Difficulty:
A and B can do a job together in 7 days. A is $1 \frac{3}{4}$ times as efficient as B. The same job can be done by A alone in :
(a)$9 \frac{1}{3}$ days
(b)11 days
(c)$12 \frac{1}{4}$ days
(d)$16 \frac{1}{3}$ days
Answer
Answer (as printed): B
Explanation
(A's 1 day's work) : (B's 1 day's work) $= \frac{7}{4} : 1 = 7:4$. Let A's and B's 1 day's work be $7x$ and $4x$ respectively. Then, $7x+4x=\frac{1}{7} \Rightarrow 11x=\frac{1}{7} \Rightarrow x=\frac{1}{77}$. $\therefore$ A's 1 day's work $= 7x = \frac{7}{77} = \frac{1}{11}$. Hence, A alone can do the job in 11 days.
Explanation as extracted from the printed page; notation may be imperfect.