A student bought 3 notebooks and 1 pen for N35. After misplacing these items, she again bought 2 notebooks and 2 pens, all of the same type for N30. What is the cost of a pen?
A. N5.00 B. N7.50 C. N10.00 D. N15.00
Correct Answer: A
Explanation
Represent notebook with x Represent pen with y ∴ 3x+y=35 ---- (i) 2x+2y=30 ---- (ii) Multiply eqn (i) by 2 and eqn (ii) by 1 6x+2y=70 ---- (iii) 2x+2y=30 ---- (iv) Subtract eqn (iv) from eqn (iii) 4x = 40 X = 10 Substitute x = 10 in eqn (i) 3x+y=35 3(10)+y=35 Y = 5 ∴ The cost of pen is N5.00
