Answer:
d. 20
Step-by-step explanation:
The given question implies 5 permutation 2, i.e 
.
But,
= 
So that for , n = 5 and r = 2.
= 
= 
= 
Cancel out 3 and 2 with respect to the numerator and denominator.
= 5 * 4
= 20
Therefore,
= 20
So that the correct option is D.
Answer:
1 hour and 15 minutes
Step-by-step explanation:
Answer:
-8x
Step-by-step explanation:
128, because it’s actually 256 but 256/ 2= 128
Answer:
a. The constant = 45
b. The unit rate is 45 miles per hour
c. d = 45t
Step-by-step explanation:
a. ∵ d ∝ t
∴ d = kt
∵ d = 90 at t = 2
∴ 90 = k(2)
∴ k = 90 ÷ 2 = 45
∴ The constant of proportionality is 45
b. ∵ k = d(miles) ÷ t(hours) = 45
∴ The unit rate is 45 miles per hour
c. The equation is ⇒ d = 45t
