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Let the cost of one pen be x and one pencil be y.
Given that, the cost of two pens are 30 Rs.
Therefore,
2x = 30
x = 30/2
x = 15Thus, the cost of one pen is 15 Rs.
Given that, Ann bought 2 pens and 5 pencils and the total cost is 80 Rs.
Therefore,
2x + 5y = 80
Substiute x = 15 in the equation,
2(15) + 5y = 80
30 + 5y = 80
5y = 80  30
5y = 50
y = 50/5
y = 10Thus, the cost of one pencil is 10 Rs.
Therefore, cost of one pen is 15 Rs. and cost of one pencil is 10 Rs.