Multiple choice

Jay goes to his grandfather's house from his own house at a speed of 4 km/hr and returns to his house at a speed of 3 km/hr. If it takes Jay 7 hours in total, find the distance between Jay's house and his grandfather's house.

  1. 7 km

  2. 12 km

  3. 15 km

  4. 20 km

  5. 24 km
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let distance be D. Time = D/4 + D/3 = 7. (3D + 4D) / 12 = 7 => 7D / 12 = 7 => D = 12 km.

AI explanation

Assume the one-way distance is D kilometers, so the total time equation is D divided by 4 plus D divided by 3 equals 7 hours. Finding a common denominator gives 3D plus 4D divided by 12 equals 7, which simplifies to 7D divided by 12 equals 7. Solving for D yields a distance of 12 kilometers.

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