Answer:
only students who have recess at 12 p.m. or later may go out
Step-by-step explanation:
Let the time after midnight be represented by t, and the temperature be y. Since the temperature increases by 1.2 degrees Fahrenheit each hour, the time taken to reach 32 degrees Fahrenheit can be gotten from:
y = 1.2t + 18
put y = 32
32 = 1.2t + 18
1.2t = 14
t = 14/1.2 = 11.67 hours
Since the recess starts at half hour or hour, hence the recess would start at t = 12 hours, i.e. at 12 p.m.
Hence only students who have recess at 12 p.m. or later may go out
Answer:
A)336
B) In how many ways can you arrange 8 people in 3 different chairs?
C) 21
D) You want to buy 3 cartoon books from a book store that has 7 cartoon books. In how many ways can you select?
Step-by-step explanation:
A) P(n, r) = P(8, 3)
Formula for permutation is;
P(n, r) = n!/(n - r)!
P(8, 3) = 8!/(8 - 3)!
P(8, 3) = (8 × 7 × 6 × 5!)/5!
5! will cancel out to give;
P(8, 3) = (8 × 7 × 6)
P(8, 3) = 336
B) In how many ways can you arrange 8 people in 3 different chairs?
C) C(n, r) = C(7, 2)
Formula for combination is;
C(7, 2) = n!/(n - r)!r!
Thus;
C(7, 2) = 7!/(7 - 2)!2!
C(7, 2) = (7 × 6 × 5!)/(5! × 2 × 1)
5! will cancel out to give;
C(7, 2) = 7 × 6/2
C(7, 2) = 21
D) You want to buy 3 cartoon books from a book store that has 7 cartoon books. In how many ways can you select?
She should have subtracted 6x from both sides to get -10x+11=1
