Change the messy words into numerals
3 times a number minus 2 equals 13
3 × n - 2 = 13
3n - 2 = 13
take 2 to the other side
3n - 2 + (2) = 13 + (2)
3n = 15
Divide by 3 on either sides to isolate n
=
3 and 3 cancels out
n = 5
check:
3 times 5 minus 2 equals 13
3 × 5 - 2 = 13
15 - 2 = 13
13 = 13
The number is 5
The sample space (list of outcomes) is:
DFNR; DFRN; DRFN; DRNF; DNFR; DNRF;
NFDR; NFRD; NRFD; NRDF; NDRF; NDFR;
RFDN; RFND; RNFD; RNDF; RDFN; RDNF;
FRDN; FRND; FNRD; FNDR; FDRN; FDNR
P(Dave beside Natalie) = 1/2
P(B,G,B,G or G,B,G,B) = 1/3
P(boys in the middle) = 1/6
P(Frida beside Natalie) = 1/2
P(Robbie between Frida & Natalie) = 1/6
P(Natalie between Dave & Robbie) = 1/6
Explanation
Letting D=Dave, R=Robbie, N=Natalie, and F=Frida you get the list of possibilites above.
For P(Dave beside Natalie), look for DN or ND. This appears 12 times out of the 24 possibilities above; 12/24 = 1/2.
For P(B,G,B,G or G,B,G,B), we have the possibilities DFRN, DNRF, RFDN, RNDF, FRND, FDNR, NDFR, NRFD. There are 8 possibilites out of 24; 8/24 = 1/3.
For P(Frida beside Natalie), look for NF or FN. This appears 12 times out of the 24 possibilities; 12/24 = 1/2.
For Robbie between Frida and Natalie, look for FRN or NRF. This appears 4 times out of 24; 4/24 = 1/6.
For Natalie between Robbie and Dave, look for RND or DNR. This appears 4 times out of 24; 4/24 = 1/6.
Answer: 2/15
Step-by-step explanation:
1/3 x 2/5 = 2/15
Answer (statistical):
1. How old are the students in this room?
2. What do 7th graders prefer to eat for lunch?
3. What time did the students in this class get up this morning?
4. What is the typical amount of pets owned by students in my class?
5. What were the high temperatures in all of the Latin American capitals today?
Answer (non-statistical):
1. What did Tom eat for lunch?
2. How old are you?
3. How many brothers does Marley have?
4. Did you get up on time today?
5. How many votes did the winning candidate for the Student Body receive this year?
