The science department buys the equipment shown in the table they bought all three items this year and how many years do they have to buy all three items again

Given that the science department buys the equipment shown in the table below.

Item                      Time Bought
Microscopes          every 5 years
Safety goggles      every 4 years
Test tubes             every 2 years

Given that they bought all three items this year. The number of years it will take for them to buy all three items again in the same year is given by the LCM of 5, 4, and 2.

5 = 1 x 5
4 = 1 x 2 x 2
2 = 1 x 2

LCM = 1 x 2 x 2 x 5 = 20.

Therefore, they will buy all three items again in 20 years.