arithmetic - a train overtakes two persons who are walking in the same direction to that of the train at 2 kmph and 4 kmph and passes them completely in 9 and 10 seconds respectively what is the length of the train - skillgun

Let x is the length of the train in meter and v is its speed in kmph
x/9 = ( v-2)(10/36) ---(1)
x/10 =( v-4) (10/36) --- (2)
Dividing equation 1 with equation 2
10/9 = (v-2)/(v-4)
=> 10v - 40 = 9v - 18
=> v = 22
Substituting in equation 1, x/9 = 200/36 => x = 9×200/36 = 50 m