Given
One warehouse had 185 tons of coal, another one had 237 tons
The first warehouse delivered 15 tons of coal to its clients daily, the second one delivered 18 tons of coal to its clients daily.
Find out in how many days will the second warehouse have 1.5 times more coal than the first one.
To proof
Let us assume that the number of days of delivered the coal = x
Take two cases
First case
As given in the question
One warehouse had coal = 185 tons
The first warehouse delivered 15 tons of coal to its clients daily
(As first warehouse delivered 15 tons of coal to its clients daily than the total amount of coal decrease daily as days increase)
Than the equation becomes for first warehouse
= ( 185 - 15x)
( this equation represent the amount of coal left after x days)
Second case
second warehouse had coal = 237 tons
the second one delivered 18 tons of coal to its clients daily.
(As first warehouse delivered 18 tons of coal to its clients daily than the total amount of coal decrease daily as days increase)
Than the equation becomes for the second warehouse
= ( 237 - 18x)
( this equation represent the amount of coal left after x days)
As given in the question
the second warehouse have 1.5 times more coal than the first one
Thus
( 237 -18x ) = 1.5× ( 185 - 15x)
237 - 18x = 277.5 - 22.5x
22.5x - 18x = 277.5 - 237
4.5x = 40.5
x = 9
Therefore the second warehouse have 1.5 times more coal than the first one in 9 days.
Hence proved
and 
