Geometric probability

Grade 10 Math Worksheet - Building Confidence

NameDate

Circle the best answer.

  1. A bird lands at a random point on Ari's 20-m fence. What is the chance it lands within 3 m of the fence's midpoint, on either side?

    • 3/17
    • 3/10
    • 3/20
    • 7/10
  2. Bo cuts a 15-ft rope at a random point. What is the chance both pieces are at least 4 ft long?

    • 8/15
    • 7/8
    • 11/15
    • 7/15
  3. Jun's 60-minute show has one ad at a random minute. What is the chance the ad is in the first 15 minutes or the last 10 minutes?

    • 5/12
    • 1/4
    • 7/12
    • 5/7
  4. Kira's yard is 8 m by 10 m, with a 3 m by 4 m sandbox. A ball lands at a random spot in the yard. What is the chance it lands in the sandbox?

    • 17/20
    • 3/20
    • 3/17
    • 7/18
  5. Luz's target mat is a circle of radius 10 cm, and the bullseye has radius 2 cm. A beanbag lands at a random spot on the mat. What is the chance it hits the bullseye?

    • 1/24
    • 24/25
    • 1/25
    • 1/5
  6. Pia's square park has 10 m sides and a round pond of radius 3 m. A raindrop lands at random in the park. Which calculation gives the chance it lands in the pond?

    • π × 3² ÷ (10² − π × 3²)
    • π × 3 ÷ 10
    • 2π × 3 ÷ (4 × 10)
    • π × 3² ÷ 10²
  7. Ren's round target has outer radius 8 cm and an inner circle of radius 5 cm. Which calculation gives the chance a random beanbag lands in the outer ring only?

    • 5² ÷ 8²
    • (8 − 5)² ÷ 8²
    • (8 − 5) ÷ 8
    • (8² − 5²) ÷ 8²
  8. A class lasts 50 minutes. Tala's fire drill starts at a random minute. Which calculation gives the chance it starts between minute 10 and minute 30?

    • 30 ÷ 50
    • (50 − 20) ÷ 50
    • 20 ÷ (50 − 20)
    • (30 − 10) ÷ 50
  9. Zee's circular spinner has a shaded sector of 120°. The arrow stops at a random spot. Which calculation gives the chance it stops in the shaded sector?

    • 120 ÷ 180
    • 120 ÷ 240
    • 120 ÷ 360
    • 240 ÷ 360
  10. A paint drop lands at random on Ari's 14 ft by 6 ft wall, which has a triangular sail (base 10 ft, height 3 ft). Which calculation gives the chance it lands on the sail?

    • (10 + 3) ÷ (14 + 6)
    • (10 × 3) ÷ (14 × 6)
    • (½ × 10 × 3) ÷ (14 × 6)
    • (½ × 10 × 3) ÷ (14 × 6 − ½ × 10 × 3)
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Geometric probability

Answer Key - Grade 10 Math Worksheet - Building Confidence

Circle the best answer.

  1. A bird lands at a random point on Ari's 20-m fence. What is the chance it lands within 3 m of the fence's midpoint, on either side?

    • 3/17
    • 3/10
    • 3/20
    • 7/10
  2. Bo cuts a 15-ft rope at a random point. What is the chance both pieces are at least 4 ft long?

    • 8/15
    • 7/8
    • 11/15
    • 7/15
  3. Jun's 60-minute show has one ad at a random minute. What is the chance the ad is in the first 15 minutes or the last 10 minutes?

    • 5/12
    • 1/4
    • 7/12
    • 5/7
  4. Kira's yard is 8 m by 10 m, with a 3 m by 4 m sandbox. A ball lands at a random spot in the yard. What is the chance it lands in the sandbox?

    • 17/20
    • 3/20
    • 3/17
    • 7/18
  5. Luz's target mat is a circle of radius 10 cm, and the bullseye has radius 2 cm. A beanbag lands at a random spot on the mat. What is the chance it hits the bullseye?

    • 1/24
    • 24/25
    • 1/25
    • 1/5
  6. Pia's square park has 10 m sides and a round pond of radius 3 m. A raindrop lands at random in the park. Which calculation gives the chance it lands in the pond?

    • π × 3² ÷ (10² − π × 3²)
    • π × 3 ÷ 10
    • 2π × 3 ÷ (4 × 10)
    • π × 3² ÷ 10²
  7. Ren's round target has outer radius 8 cm and an inner circle of radius 5 cm. Which calculation gives the chance a random beanbag lands in the outer ring only?

    • 5² ÷ 8²
    • (8 − 5)² ÷ 8²
    • (8 − 5) ÷ 8
    • (8² − 5²) ÷ 8²
  8. A class lasts 50 minutes. Tala's fire drill starts at a random minute. Which calculation gives the chance it starts between minute 10 and minute 30?

    • 30 ÷ 50
    • (50 − 20) ÷ 50
    • 20 ÷ (50 − 20)
    • (30 − 10) ÷ 50
  9. Zee's circular spinner has a shaded sector of 120°. The arrow stops at a random spot. Which calculation gives the chance it stops in the shaded sector?

    • 120 ÷ 180
    • 120 ÷ 240
    • 120 ÷ 360
    • 240 ÷ 360
  10. A paint drop lands at random on Ari's 14 ft by 6 ft wall, which has a triangular sail (base 10 ft, height 3 ft). Which calculation gives the chance it lands on the sail?

    • (10 + 3) ÷ (14 + 6)
    • (10 × 3) ÷ (14 × 6)
    • (½ × 10 × 3) ÷ (14 × 6)
    • (½ × 10 × 3) ÷ (14 × 6 − ½ × 10 × 3)