Aptitude Discussion

Q. |
If 1 added to the age of the elder sister, then the ratio of the ages of two sisters becomes $0.5 : 1$, but if 2 is subtracted from the age of the younger one, the ratio becomes $1:3$, the age of the younger sister will be? |

✖ A. |
7 year |

✔ B. |
5 year |

✖ C. |
8 year |

✖ D. |
10 year |

**Solution:**

Option(**B**) is correct

Suppose that age of elder sister be $x$ year, and younger sister be $y$ year. Then:

\(\dfrac{y}{x+1}=\dfrac{0.5}{1}=\dfrac{1}{2}\)

\(\Rightarrow x-2y=-1\)-------(i)

Again given:

\(\dfrac{y-2}{x}=\dfrac{1}{3}\)

\(\Rightarrow x-3y=-6\)-------- (ii)

From both the equations we get:

$x=9$ and $y=5$

So, the age of younger sister is **5 years**