Question

a tailor uses 2 metre 20 CM of cloth for a shirt. How long of cloth will be required for 18 such shirts?

Answer 1

the answer is that 39 m and 60 cm of cloth will be required

Answer 2

cloth material used for 1 shirt = 2 m 20 cm (2m = 200cm +20cm)
                                                = 220cm
                            for 18 shirts = 18 x  220 cm
                                                = 3960 cm