Question

If 7 pens cost $ 4.20, what is the cost of 3 pens

Answer 1

7......4.20

3......x

x = (3 * 4.20)/7 = 3 * 0.6 = $ 1.2

Answer 2

7 pen cost 4.20
1pen cost 4.20/7
3pen cost 4.20/7×3=1.8

₹1.8 cost for 3 pens