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Distance between A and B is 60 kms. When...

Distance between A and B is 60 kms. When they move in opposite direction they meet in 6 hours. If A moves at 2/3rd of its actual speed and B at 2 times of its speed then they meet in 5 hours what are their respective speed.

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To solve the problem step by step, we will define the speeds of A and B, set up equations based on the information provided, and then solve those equations. ### Step 1: Define the Speeds Let the speed of A be \( S_A \) km/h and the speed of B be \( S_B \) km/h. ### Step 2: Set Up the First Equation When A and B move in opposite directions, they meet in 6 hours. The total distance between A and B is 60 km. The relative speed when moving in opposite directions is the sum of their speeds: \[ S_A + S_B = \frac{\text{Distance}}{\text{Time}} = \frac{60 \text{ km}}{6 \text{ hours}} = 10 \text{ km/h} \] Thus, we have our first equation: \[ (1) \quad S_A + S_B = 10 \] ### Step 3: Set Up the Second Equation In the second scenario, A moves at \( \frac{2}{3} \) of its actual speed and B moves at \( 2 \) times its speed. They meet in 5 hours: \[ \frac{2}{3} S_A + 2 S_B = \frac{60 \text{ km}}{5 \text{ hours}} = 12 \text{ km/h} \] This gives us our second equation: \[ (2) \quad \frac{2}{3} S_A + 2 S_B = 12 \] ### Step 4: Solve the Equations Now we have a system of equations: 1. \( S_A + S_B = 10 \) 2. \( \frac{2}{3} S_A + 2 S_B = 12 \) From equation (1), we can express \( S_B \) in terms of \( S_A \): \[ S_B = 10 - S_A \] ### Step 5: Substitute \( S_B \) in the Second Equation Substituting \( S_B \) in equation (2): \[ \frac{2}{3} S_A + 2(10 - S_A) = 12 \] Expanding this gives: \[ \frac{2}{3} S_A + 20 - 2 S_A = 12 \] ### Step 6: Combine Like Terms To combine like terms, convert \( 2 S_A \) into thirds: \[ \frac{2}{3} S_A - \frac{6}{3} S_A + 20 = 12 \] This simplifies to: \[ -\frac{4}{3} S_A + 20 = 12 \] ### Step 7: Isolate \( S_A \) Subtract 20 from both sides: \[ -\frac{4}{3} S_A = 12 - 20 \] \[ -\frac{4}{3} S_A = -8 \] Multiplying both sides by -1: \[ \frac{4}{3} S_A = 8 \] Now multiply both sides by \( \frac{3}{4} \): \[ S_A = 8 \times \frac{3}{4} = 6 \text{ km/h} \] ### Step 8: Find \( S_B \) Now substitute \( S_A \) back into equation (1) to find \( S_B \): \[ S_B = 10 - S_A = 10 - 6 = 4 \text{ km/h} \] ### Final Answer The speeds of A and B are: - Speed of A, \( S_A = 6 \) km/h - Speed of B, \( S_B = 4 \) km/h
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