Jawapan

2016-08-07T14:34:08+08:00
2πj = 2 × (22/7) × 6400km
= 40228/4/7km

40228/4/7km ÷ 4.2m= 40228571.43m ÷ 4.2m
= 9578231.293

∴ 9578231 buah kereta