Answer:
45 rupees
Explanation:
If the cost of 12 pens is 108 rs, then we need to find the cost for 1 pen. We can divide the 108 rupees by 12 to find the cost per pen. We get 9; now we know that each pen costs 9 rupees and we have 5 pens so 9 times 5 is 45 rupees.