Question

If 7pens cost 4.20 what is the costof 3pens

Answer 1

cost of one pen is 0.6 and 3 pens is 1.8

Answer 2

cost of 7= 4.20

therefore , cost of 1 = 4.2/7 =0.6

therefore cost of 3 pens = 3 * 4.2/7 = 3*0.6= 1.8 rupees