Answer: 5 pens cost Rs.50
Explanation: Since 1 pen costs Rs.10, you will need to multiply the number of pens (1) and the cost of that number of pens (Rs.10) by the amount of pens you must find the cost for (5). Since 10 times 5 is 50, that means that 50 is the cost of 5 pens.
I hope this helps!
