Answer:
1.) 12000
2.) 6750
3.) 2.41
Step-by-step explanation:
Given the Equation :
f(t)=12,000(3/4)^t. ; where, t = time ; f(t) = worth of car at time, t
When, car was purchased, t = 0
t = 0
f(0) = 12000(3/4)^0
= 12000 * 1
= 12000
2.)
f(2) ; this mean the worth of the car after 2 years :
f(2)=12,000(3/4)^t.
12000(3/4)^2
12000 * 0.5625
= 6750
When car will be worth 6000
f(t) = 6000
f(t)=12,000(3/4)^t.
6000 = 12,000(3/4)^t
6000 / 12000 = (3/4)^t
1/2 = (3/4)^t
Take the log of both sides :
Log(0.5) = log(0.75)^t
log(0.5) = tlog(0.75)
- 0.301029 = - 0.124938t
t = - 0.301029 / - 0.124938
t = 2.4094
t = 2.41 years
Answer:
8 and 6
Step-by-step explanation:
Two numbers are such that their difference, their sum, and their product are to
each other as 1:7:24. Their product must equal what number?
:
Two numbers a & b
Let x = the multiplier
:
a - b = 1x
a + b = 7x
a * b = 24x
:
Add the 1st two equations
a - b = x
a + b = 7x
2a = 8x
a = 4x
or
x = .25a
:
a * b = 24x
Replace 24x; a = 4x therefore:
a * b = 6a
b = 6
;
Using the 1st equation
a - b = 1x
Replace b with 6 and x with .25a
a - 6 = .25a
a - .25a = 6
.75a = 6
a =
a = 8
:
Find the multiplier
a - b = x
8 - 6 = 2
:
Check this
a - b = 2 (1*2)
a + b = 14; (7*2)
a * b = 48: (24*2)
:
The numbers are 8 and 6; their products = 48
Reggie’s speed = distance/time
Reggie’s speed = 40.2 / 2.5
Reggie’s speed = 16.08 mi/hr
Craig’s speed = distance/time
Craig’s speed = 30.8 / 1.875
Craig’s speed = 16.43 mi/hr
Hence, answer is Craig
Answer:
the digit two is in tens... so a) is the answer