Extra Set

Grade 7 · Unit 7 · L30 · Version A · 78E0

Probability

Name ________________

Date ________________

Period ________________

1.
A bag has 6 red and 4 blue marbles. One marble is drawn at random. P(red)?
Answer. 35
Favorable 6 / total 10 = 35.
2.
A bag has 6 red and 5 blue marbles. One marble is drawn at random. P(red)?
Answer. 611
Favorable 6 / total 11 = 611.
3.
A bag has 5 red and 5 blue marbles. One marble is drawn at random. P(red)?
Answer. 12
Favorable 5 / total 10 = 12.
4.
A bag has 5 red and 2 blue marbles. One marble is drawn at random. P(red)?
Answer. 57
Favorable 5 / total 7 = 57.
5.
A bag has 5 red and 6 blue marbles. One marble is drawn at random. P(red)? Then Grace needs 5 of that amount. What is the total they need?
Answer. 2311
Favorable 5 / total 11 = 511. Then multiply by 5: 2311.
6.
A bag has 5 red and 6 blue marbles. One marble is drawn at random. P(red)? Then Grace needs 5 of that amount. What is the total they need?
Answer. 2311
Favorable 5 / total 11 = 511. Then multiply by 5: 2311.
7.
A bag has 5 red and 2 blue marbles. One marble is drawn at random. P(red)? Then Theo needs 3 of that amount. What is the total they need?
Answer. 217
Favorable 5 / total 7 = 57. Then multiply by 3: 217.
8.
A bag has 5 red and 4 blue marbles. One marble is drawn at random. P(red)? Then Sam needs 4 of that amount. What is the total they need?
Answer. 229
Favorable 5 / total 9 = 59. Then multiply by 4: 229.
9.
A bag has 5 red and 2 blue marbles. One marble is drawn at random. P(red)? Then Ava needs 4 of that amount. What is the total they need?
Answer. 267
Favorable 5 / total 7 = 57. Then multiply by 4: 267.
10.
A bag has 3 red and 2 blue marbles. One marble is drawn at random. P(red)? Then Theo needs 2 of that amount. What is the total they need?
Answer. 115
Favorable 3 / total 5 = 35. Then multiply by 2: 115.
11.
Think
Luis tried this problem:
A bag has 5 red and 4 blue marbles. One marble is drawn at random. P(red)?
Luis wrote 510. That is not correct. What is the right answer?
Answer. 59
Luis’s answer 510 is off. Favorable 5 / total 9 = 59.
12.
Think
Luis tried this problem:
A bag has 5 red and 3 blue marbles. One marble is drawn at random. P(red)?
Luis wrote 59. That is not correct. What is the right answer?
Answer. 58
Luis’s answer 59 is off. Favorable 5 / total 8 = 58.

Original extra practice. Keys are computed from the items, not guessed.

L30 · Probability