The radius of a circle is half the length of the circumference.
So multiply 12 by itself and you get 24.
The answer is C.
The lines have equal gradients;
m
Equation of line 2;
y=mx+c
y=
x+c
-15=
+c
c=-11
y=4/5x-11
Step-by-step explanation:
The easiest approach is to realise that one hour is 3 times longer than
20
minutes. The longer the time, the more they will pave.
2
15
of a mile, in 20 minutes, how much in 60 minutes?#
They will pave 3 times more.
2
15
×
3
1
=
6
15
of a mile
6
15
=
2
5
of a mile
You could also use the 'unitary method' where you find out how much they pave in ONE minute (divide by
20
) and them multiply by
60
to find how much in one hour.
Look at what happens:
2
15
÷
20
×
60
=
2
15
×
1
20
×
60
3
=
2
15
×
3
←
exactly the same maths.
=
2
5
Answer: it will take the faster computer 15 minutes to do the job on its own.
Step-by-step explanation:
Let t represent the number of minutes it will take the faster computer to do the job on its own. It means that the rate at which it does the job per minute is 1/t
If it takes the slower computer 30 minutes to do the job on its own. It means that the rate at which it does the job on its own per minute is 1/30
By working together, they would work simultaneously and their individual rates are additive. Working together it takes two computers 10 minutes to send out a company's email. It means that the rate at which both computers work together per minute is 1/10 Therefore,
1/t + 1/30 = 1/10
Cross multiplying by 30x, it becomes
3x = x + 30
3x - x = 30
2x = 30
x = 30/2
x = 15 minutes
