Answer:Explanation:
Using first principles
Assumption: the increase is to be expressed as a percentage of 10.
We change from 10 to 13 so the increase is 3
We now need to change this into a percentage.
In fraction form we have
increase
Original value
→
3
10
But we need to change this into the form
some number
100
Let the unknown value be
x
giving:
3
10
≡
some number
100
=
x
100
To change the 10 from
3
10
into 100 we multiply by 10
Multiply by 1 and you do not change the value. However, 1 comes in many forms.
3
10
×
1
=
3
10
×
10
10
=
30
100
This is the same as
30
×
1
100
but
1
100
is the same as %
.
So
30
100
→
30
%
Step-by-step explanation:
