Question

The cost of $1dozen$ gel pens is $₹144$ and the cost of $9$ ball pens is $₹81$. Find the ratio of the cost of $5$ gel pens to the cost of $4$ ball pens.

Answer 1

Step 1: Find the cost of $5$ gel pen

$1dozen=12$

Cost of $12$ gel pens is $₹144$

Cost of $1$ gel pens is $₹\frac{144}{12}=₹12$

Cost of $5$ gel pens is $₹12\times 5=₹60$

Step 2: Find the cost of $4$ ball pen

Cost of $9$ ball pens is $₹81$

Cost of $1$ ball pens is $₹\frac{81}{9}=₹9$

Cost of $4$ ball pens is $₹9\times 4=₹36$

Step 3: Find the ratio

ratio of the cost of $5$ gel pen to the cost of $4$ ball pen = $\frac{60}{36}=\frac{60÷12}{36÷12}=\frac{5}{3}=5:3$

Hence, ratio of the cost of $5$ gel pen to the cost of $4$ ball pen is $5:3$.