Question

When I bought the pen and pencil, it cost Rs.75. When I bought the pencil and scale, it cost Rs 48. When I bought the pen and scale, it cost 63 rupees. So how much does a pen cost?​

Answer 1

Answer:

₹ 45

Step-by-step explanation:

Let pen = x

Let pencil = y

Let Scale = z

y + z = 48

    y = 48 - z     ⇒ eq. 1

x + z = 63

    x = 63 - z     ⇒ eq. 2

x + y = 75

Replacing,

(63 - z) + (48 - z) = 75

                    -2z = 75 - 63 - 48

                    -2z = (-36)

                       z = 36 ÷ 2 = 18

x + z = 63

x + 18 = 63

x = 63 - 18 = 45