Question

A cell phone company orders 500 new phones from a manufacturer. If the probability of a phone being defective is 2.6%, predict how many of the phones are likely to be defective. Round to the nearest whole number.

A. 16 phones
B. 130 phones
C. 13 phones
D. 11 phones

Answer 1

2.6% of the phones are deffective, can you work out 2.6 of 500?

Answer 2

How would I do that?

Answer 3

To work out a percentage of a number you do
\[number \times \frac{ percentage }{ 100 }\]

Answer 4

13 phones.

Answer 5

Correct

Answer 6

What about this one, it's the same just without a percentage.

Answer 7

In a batch of 890 calculators, 12 were found to be defective. What is the probability that a calculator chosen at random will be defective? Write the probability as a percent. Round to the nearest tenth of a percent if necessary.

Answer 8

A. 98.7%
B. 1.3%
C. 74%
D. 1.8%

Answer 9

So 12 out of 890 are defective. 12/890

Answer 10

I got 0.013 in my calc.

Answer 11

So 13?

Answer 12

Wait.
whoops. looking at the first questions answers lmfao

Answer 13

so, 1.3?

Answer 14

0.013 is the probability that you will get a defective one. To turn this into a percentage you multiply this by 100.

Answer 15

Yep. I got 1.3 :D

Answer 16

well done

Answer 17

I get this now. But can I do one more ?

Answer 18

Yes

Answer 19

You have the numbers 1-24 written on slips of paper. if you choose one slip at random, what is the probability that you will not select a number which is divisible by 3?

A. 2/3
B. 3/8
C. 1/3
D. 5/8

Answer 20

Which numbers between 1 and 24 are divisible by 3? Well 3,6,9,12,15,18,21,24.
So any of these 8 numbers out of the 24 will do the job

Answer 21

So we could use 24 then?

Answer 22

3x8 = 24

Answer 23

So b, 3/8?

Answer 24

Was wrong. :p

Answer 25

No actually, 8 out of 24 is not 3/8

Answer 26

Yeah that was my fault.

Answer 27

8/24 = 1/3