Question

Yesterday, Candice and Sabrina trained for a bicycle race by riding around an oval track. They both began riding at the same time from the track's starting point. However, Candice rode at a faster pace than Sabrina, completing each lap around the track in 42 seconds, while Sabrina completed each lap around the track in 46 seconds. How many laps around the track had Candice completed the next time that Candice and Sabrina were together at the starting point?
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Answer Choices

  • A.
    21
  • B.
    23
  • C.
    42
  • D.
    46
  • E.
    483

Steps

ExplanationCalculationsHelp
We first factor each rider's lap time into prime numbers.
We now find the least common multiple of the two lap times by taking each prime with its highest needed exponent.
Theory & Tactics Method Card
DIV6-A
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Candice's number of laps equals the total time until they meet divided by her lap time, so we write this division in factored form before simplifying.
Theory & Tactics Method Card
FDPR2-A
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We cancel out the common factors to obtain Candice's lap count.
Theory & Tactics Method Card
FDPR2-A
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Final Answer

23