Perimeter of the back wheel = 9 feet, front wheel = 7 feet. Through a certain…

2023

 Perimeter of the back wheel = 9 feet, front wheel = 7 feet. Through a certain distance, the front wheel gets 10 revolutions more than the back wheel. What is the distance?

  1. A.

    16 Feet

  2. B.

    1980 Feet

  3. C.

    63 Feet

  4. D.

    315 feet

Attempted by 6 students.

Show answer & explanation

Correct answer: D

Revolutions by a wheel = Distance covered / Circumference

Circumference of wheel = Perimeter of wheel

According to question

Revolutions by front wheel - Revolutions by back wheel = 10

⇒ (Distance covered / Circumference of front wheel) - (Distance covered / Circumference of back wheel) = 10

⇒ (Distance Covered ) { (1 / Circumference of front wheel ) - (1 / Circumference of back wheel)} = 10

⇒ (Distance Covered ) { (1 / 7 ) - (1 / 9)} = 10

⇒ (Distance Covered ) { (2 /63 ) } = 10

⇒ (Distance Covered ) = 630 / 2 = 315

Hence Option (D)

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