two trains start at the same time from points A and B towards each other and after crossing each other,detect 25 hours and nine hours in reaching points B and a respectively.find the ratio of speeds of train starting from A to that of starting from B .
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Answer:
3: 5
Step-by-step explanation:
Let say Distance between A & B is D km
Speed of Train starting from A = A km/Hr
Speed of Train Starting from B = B km/Hr
Let say after T hr they crossed each other
=> AT + BT = D - eq 1
=> T = D/(A+B)
A ( T + 25) = D => AT + 25A = D - eq2
B ( T + 9) = D => BT + 9B = D - eq 3
Eq 2 + eq3 - eq 1
=> 25A + 9B = D
=> 25A + 9B = AT + BT - eq 4
Eq 2 - E3
AT - BT + 25A - 9B = 0
=> 25A - 9B = BT - AT - eq 5
Adding eq 4 & eq 5
50A = 2BT
=> 25A = BT - eq 6
Eq 4 - Eq 5
18B = 2AT
=> 9B = AT - eq 7
eq6/eq7
25A/9B = BT/AT
=> 25A/9B = B/A
=> 25A² = 9B²
=> A²/B² = 9/25
=> A/B = 3/5
A: B :: 3: 5
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