Answer: 78 rupees
Explanation: since 10 pens cost 60 rupees you can divide 60 by 10 to get the cost of a single pen. The cost of a single pen is 6 rupees so you can multiply that by 13 to find the cost of the 13 pens.
10p=60
60/10=6
p=6
so
13x6=78
Hope this helped! :)