5 pens and 6 pencils together cost Rs 9 and 3 pens and 2 pencils cost Rs 5. Find the cost of 1 pen and 1 pencil.
Let the cost of 1 pen be ‘a’ and the cost of 1 pencil be ‘b’.
Given, 5 pens and 6 pencils together cost Rs 9.
5a + 6b = 9 --------- (1)
Given, 3 pens and 2 pencils cost Rs 5.
3a + 2b = 5 -------- (2)
Multiplying eq2 by 3 and subtracting eq1 from it.
⇒ 9a + 6b – 5a – 6b = 15 – 9
⇒ 4a = 6
⇒ a = 3/2
Substituting value of 'a' in (1)
⇒ 15/2 + 6b = 9
⇒ 6b = 3/2
⇒ b = 1/4