Three times a number, subtracted from 20, is equal to -7
1 answer:
You might be interested in
Answer:
Step-by-step explanation:
From the given information.
suppose a multiple choice test consists of 5 questions, each with 4 possible answers of which 1 is correct.:
So, we can now suggest that a person can answer each question in 4 different ways given that there are 5 different questions.
Thus, the students can check off one answer to each question in
= 4 × 34 × 4 × 4 × 4
= 1024 different ways.
From the 4 possible answers, since 1 will be correct, definitely 3 other answers will be incorrect.
Thus, the number of ways a student can check off one answer to each question and get all the answers wrong is = 3⁵
= 3 × 3 × 3 × 3 × 3
= 243 ways
(a) Animals by popularity; Dogs, Cats, Others, Horses.
(b) If 250 students were interviewed, 20 students have other pets.
(c) No, it was incorrect.
Step-by-step explanation:
Step 1; We arrange the different pets in chronological order, from the highest percent to the lowest percent;
1. Dogs - 67%,
2. Cats - 20%
3. Others - 8%,
4. Horses - 1%.
None is not included in this list.
Step 2; If 250 students were interviewed, 8% of those have other pets. So we need to calculate how much 8% of 250 is.
8% of 250 = × 250 = 0.08 × 250 = 20.
So 20 students had other pets.
Step 3; 20% of the interviewed students had cats. If 75 students had cats, we need to equate 20% to the 75 and find out how many students were actually interviewed.
20% × x = 75, 0.2 × x = 75,
x = = 375.
So if 375 students were interviewed, 75 students would have cats. So the estimate of 250 students being interviewed is incorrect.