Given,
25 passengers are equal to 71.428% of total capacity of wagon.
Means, 71.428% passengers =25.
1% passengers =2571.428
Hence, 100% passengers =25×10071.428=35 passengers.
Capacity of one wagon =35
So, number of wagon =35.
Total capacity of the train =35×35.
Also, given 20% seat remains vacant.
Thus, the number of passengers in the train,
=1225−(20100×1225)=1225−245=980.