Answer:
y = 2x - 3
Step-by-step explanation:
Answer:
<u>The ages of Paul and Selena are 13 and 7 years old.</u>
Step-by-step explanation:
Age of Paul = x
Age of Selena = x -6
Age of Paul and Selena in 15 years:
x + 15 = 4 (x - 6)
x + 15 = 4x - 24
x - 4x = -24 - 15
- 3x = -39
x = 13
<u>Paul now is 13 years old and Selena is 7 years old. In 15 years, Paul will be 28, that is 4 times the present age of Selena.</u>
Answer: The first one
Step-by-step explanation:
Answer:
1287
Step-by-step explanation:
Number of people in elevator , n = 8
Number of floors, r = 6
Since they all look alike, arrangement doesn't matter, the we use combination :
(n+r-1 r - 1) = (8+6-1 C 6-1) = 13C5
Recall:
nCr = n! / (n-r)!r!
13C5 = 13! / (13-5)!5!
13C5 = 13*12*11*10*9 / 5*4*3*2*1
= 1287
