Answer:
Number : 42
Step-by-step explanation:
This number will be a two - digit number, and hence we can say that it is yz. The ratio of the units digit to the tens digit is given by 1 / 2, so z / y = 1 / 2.
In addition the tens digit is 2 more than the units digit, so y = z + 2. We therefore have the following system of equations,
y = z + 2,
z / y = 1 / 2
Substituting the first equation into the second we receive z / z + 2 = 1 / 2. Using this we can solve for z.
z / z + 2 = 1 / 2 ( Cross - Multiply )
z + 2 = 2z, z = 2
And knowing z we can solve for y. y = z + 2 = 2 + 2 = 4. Therefore our number is 42.
the answer is c you just have to solve each one
Answer:
A
Step-by-step explanation:
It is making me add 20 characters to my answer so ignore this :)
Answer:
the rate of each train is 139 km/h and 159 km/h.
Step-by-step explanation:
let
v = the rate of the slower train
v + 20 = the rate of the faster train
d = 1490 km the distance that the two train will travel
t = 5 hr the time of the travel
since speed = distance/time => distance = speed*time
v*t + (v+20)t = d
5v + 5(v + 20) = 1490
5v+5(v+20)=1490
Step 1: Simplify both sides of the equation.
5v+5(v+20)=1490
5v+(5)(v)+(5)(20)=1490(Distribute)
5v+5v+100=1490
(5v+5v)+(100)=1490(Combine Like Terms)
10v+100=1490
10v+100=1490
Step 2: Subtract 100 from both sides.
10v+100−100=1490−100
10v=1390
Step 3: Divide both sides by 10.
10v/10 = 1390/10
v = 139km/h
Next
we add 139 to 20
139 + 20 = 159 km/h
the rate of each train is 139 km/h and 159 km/h.
Answer:
2/3
Step-by-step explanation:
