Data and probability · Ages 14–15

Equally likely outcomes worksheet

Part of: Probability

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Data and probability · Ages 14–15

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Name:Date:Score:／48

Write each answer in the space. For word problems, show your working and write a sentence answer.

1.A bag holds 4 red balls (R), 4 blue (B) and 2 yellow (Y), as shown. One is drawn at random. The probability of blue is .
Answer in simplest form
Answer:
2.Ka-lok rolls a fair die. The probability of a number greater than 5 is .
Answer in simplest form
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3.There are 8 number cards on the table, as shown. Turned over and shuffled, one is drawn at random. The probability of an even number is .
Answer in simplest form
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4.May rolls a fair die. The probability of a number greater than 5 is .
Answer in simplest form
Answer:
5.A bag holds 5 red balls (R), 1 blue (B) and 4 yellow (Y), as shown. One is drawn at random. The probability of blue is .
Answer in simplest form
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6.A spinner has 6 equal parts with the numbers shown. Spun once, the probability it stops on an odd number is .
Answer in simplest form
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7.A whole number from 1 to 23 is chosen at random. The probability of a multiple of 5 is .
Answer in simplest form
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8.A bag holds 2 red balls, 9 blue and 4 green. One is drawn at random: P(red) = , P(not red) = .
Fill in each blank
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9.A box holds 4 red balls and 3 blue ones. One is drawn at random. What is the probability of red?
- A. 37
- B. 47
- C. 17
- D. 43
Choose the right answer
Answer:
10.A box holds 6 red balls and 7 blue ones. One is drawn at random. What is the probability of red?
- A. 113
- B. 713
- C. 613
- D. 67
Choose the right answer
Answer:
11.12 cards are numbered 1 to 12, and one is drawn at random. A prime is less likely than an odd number.
True or false?
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12.8 cards are numbered 1 to 8, and one is drawn at random. A prime is less likely than an odd number.
True or false?
Answer:

13.A fish tank has 4 goldfish and 4 tropical fish. 1 more goldfish go in, then one fish is netted at random. What is the probability it is a goldfish?
Answer in simplest form
Working:
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14.A party's raffle numbers run from 1 to 48, and a multiple of 4 wins a small gift. Ming draws one number. What is the probability of a gift?
Answer in simplest form
Working:
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15.A lucky-draw box holds 35 tickets: 4 first prizes, 6 second prizes and the rest blanks. Ka-yee draws one. What is the probability of a prize?
Answer in simplest form
Working:
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16.A box of chocolates has 9 nut, 2 strawberry and 6 mint, all looking alike. There are in the box; taking one at random, the probability of strawberry is .
Fill in each blank
Working:
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17.A stall's lucky spinner has 8 equal parts, each number a prize in dollars, as shown. Spun once, the probability of winning at least 20 dollars is , and of winning nothing .
Fill in each blank
Working:
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18.A party's raffle numbers run from 1 to 77, and a multiple of 7 wins a small gift. Tsz-hin draws one number. What is the probability of a gift?
Answer in simplest form
Working:
Answer:

Show the answers and working

Equally likely outcomes worksheet: Answers and working

1. 25
There are 4 + 4 + 2 = 10 balls, 4 of them blue: 410 = 25.
2. 16
1 of the 6 outcomes are greater than 5: 16 = 16.
3. 12
4 of the 8 cards are even: P(even) = 48 = 12.
4. 16
1 of the 6 outcomes are greater than 5: 16 = 16.
5. 110
There are 5 + 1 + 4 = 10 balls, 1 of them blue: 110 = 110.
6. 13
2 of the 6 equal parts are odd: 26 = 13.
7. 423
23 ÷ 5 has whole part 4, so there are 4 multiples of 5: 423 = 423.
8. 215, 1315
15 balls: P(red) = 215 = 215; P(not red) = 1 − 215 = 1315, or count the 9 + 4 straight.

9. B. 47
There are 7 balls, 4 of them red: P(red) = 47.
10. C. 613
There are 13 balls, 6 of them red: P(red) = 613.
11. True
From 1 to 12 there are 5 primes and 6 odd numbers; over the same 12, just compare the counts.
12. False
From 1 to 8 there are 4 primes and 4 odd numbers; over the same 8, just compare the counts.

Marking: 2 for the working, 1 for the answer, 1 for the sentence.

13. 59
Goldfish: 4 + 1 = 5 of 9 fish: 59 = 59.
14. 14
48 ÷ 4 has whole part 12: 12 multiples of 4, P = 1248 = 14.
15. 27
Prizes: 4 + 6 = 10 tickets: 1035 = 27.
16. 17, 217
9 + 2 + 6 = 17; strawberry 2: 217 = 217.
17. 18, 58
The 8 parts are equally likely: 1 pay at least 20 dollars, P = 18; 5 pay 0, P = 58.
18. 17
77 ÷ 7 has whole part 11: 11 multiples of 7, P = 1177 = 17.

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