I am working in a bus company. The company recently went under expansion and therefore there was not enough room for all the buses. As a result, twelve buses had to be stored outside.
If the company decides to expand the garage space by forty percent, enough space to accommodate the current buses will be created leaving enough space for twelve more buses if the need arises in future.
Can you calculate the number of buses that the company owns at present?
The company owns seventy two buses at present.
Let us assume that they have B buses right now and S space before the expansion. Now the space is enough for
S = B - 12 ----- 
When they expand, they will have more space which will be enough for
S + 0.4 x S = B + 12 ------ 
=> 1.45 = B + 12
Also, B = 1.45 - 12 ----- 
Now we can rewrite the equation  as
B = S + 12 ----- 
Equating the third and fourth equation, we get
1.4 S - 12 = S + 12
Subtract S from both sides
0.4 S - 12 = 12
Now add 12 to both sides
0.4 S = 24
Multiply by ten and divide by four on both sides
S = 60
Put the value in fourth equation
B = 72