Given
During a promotional event
A sporting goods store gave a free t-shrit to every 8th customer and a free water bottle to every 10th customer.
Find out which customer has the first to get a free t-shirt and a free water bottle.
To proof
Definition of LCM ( Least common multiple )
The LCM of two numbers is the smallest number that they both divide evenly into.
As given in the equation
A sporting goods store gave a free t-shrit to every 8th customer and a free water bottle to every 10th customer.
Let take 8 be as one number and 10 be as another number.
LCM ( 8,10 ) = 2× 2 ×2 ×5
= 40
Also
A sporting goods store gave a free t-shrit to every 8th customer and a free water bottle to every 10th customer.
This is shown in the table given below.
As shown in the table the common value is 40.
Therefore
The first to get a free t-shirt and a free water bottle is 40th customer.
Hence proved