The cost of 5 pens and 3 pencils is Rs. 94. If the cost of a pen is increased by Rs. 2 and the cost of a pencil is decreased by Rs. 1, then the cost of 2 pens and 7 pencils is Rs. 52. What is the original cost of 3 pens and 8 pencils?
1
Rs. 75
2
Rs. 85
3
Rs. 80
4
Rs. 70