In a kilometre race, A, B and C are three participants. A can give B a start of 50 m and C a start of 69 m… · ABC26GN5116
Subject: General Aptitude · Chapter: Races and Games of Skill · Exam: S.S.C. 2006
In a kilometre race, $A, B$ and $C$ are three participants. $A$ can give $B$ a start of 50 m and $C$ a start of 69 m . The start which $B$ can allow $C$, is
(a)17 m
(b)18 m
(c)19 m
(d)20 m
Answer
Answer (as printed): D
Explanation
$$\begin{aligned} & A: B: C=1000:(1000-50):(1000-69) \\ & \quad=1000: 950: 931 . \end{aligned}$$ In a 950 m race, $B$ can give $C$ a start of (950-931) $\mathrm{m}=19 \mathrm{m}$. In a 1000 m race, $B$ can give $C$ a start of $\left(\frac{19}{950} \times 1000\right) \mathrm{m}=20 \mathrm{m}$.