A train would take 45 seconds to cross a

Solution

let the original length of the train = x m ∴ Speed of the original train = [if gte msEquation 12]> x 45 [if !msEquation]--> [endif]-->`x/45` m/s ∴ Length of the longer train =`x+100` [if gte msEquation 12]>x+100 [if !msEquation]--> [endif]--> ∴ speed of the longer train = [if gte msEquation 12]> x+100 65 [if !msEquation]--> [endif]-->`(x+100)/65` m/s Since, both the train are same their speed are also same ∴ [if gte msEquation 12]> x 45 [if !msEquation]--> [endif]-->`x/45` =`(x+100)/65` [if gte msEquation 12]> x + 100 65 [if !msEquation]--> [endif]--> ⟹ 65 x = 45x [if gte msEquation 12]> x [if !msEquation]--> [endif]-->+ 4,500 ⟹ 20 x = 4,500 ⟹ [if gte msEquation 12]>x [if !msEquation]--> x = 225 ∴ Speed = `x/45` [if gte msEquation 12]> x 45 [if !msEquation]--> [endif]-->=`225/45` [if gte msEquation 12]> 225 45 [if !msEquation]--> [endif]-->= 5m/s