**PUZZLE**

A stationery shop sells 8 pens and 2 whiteboard markers for Ghc46.00. If the shop also sells 7 pens and 3 markers for Ghc47.00. What is the cost of one pen and one marker?

**ANSWER**

**Preambles: **8 pens + 2 markers = Ghc46.00; 7 pens + 3 markers = Ghc47.00;** 1 pen =?** **1 marker =?**

**Step 1: **Denote the price of 1 pen by *x *and the price of 1 marker by *y. *

**Step 2: **From the preamble, *8x+2y = 46, thus 4x+y = 23…..(equation 1)*

Also, **7x+3y=47……(equation 2)**

**Step 3: **From eqn 1, *y = 23 – 4x…..(equation 3).*

* *Substituting this into equation 2, expanding the brackets and solving for x: *7x + 3(23-4x) =47; thus, 7x -12x = 47 -69, therefore, 5x = 22x = 4.4*

**Step 4: **Substitute the value of x into equation 3 to get the value of y. **Thus y = 23 – 4(4.4); y = 23 – 17.6. y = 5.4**

**Therefore, 1 pen costs Ghc4.40 and 1 marker cost Ghc5.40.**

**CHALLENGE YOURSELF**

At these prices how much would it cost to purchase 1 pack of pen and 2 packs of markers? A pack of pens contains 50 pieces of pens and a box of the marker contains twelve pieces of markers.