Astudent can eat 4.0 m& ms every 1.00 seconds. if an m& m has a mass of 63g, determine how many kilograms of m& ms can be eaten by a class of 20 students in 3.75 hours.

To be able to determine the right answer to this item, we simply have to use the proper conversion factors and dimensional analysis. 

First, we calculate for the total number of M&M that the 20 students can eat in 1 second considering that each student can eat 4.
           n = (20 students)( 4 M&Ms / student )
                 n = 80 M&M

Then, we calculate for the mass of 80 M&M given that each weighs 63 g.
              mass = (80 M&M)(63 g/ 1 M&M) = 5040 g of M&M

Next, we solve for the total mas of M&M that can be eaten in 3.75 hours considering that one hour is equivalent to 3600 seconds.
               total mass = (5040 g M&M/s)(3600 s/1 h)(3.75)
                   total mass = 68040000 g of M&M

Converting this to kilogram by dividing it by 1000 will give us an answer of,
                     total mass = 68040 kg of M&M

Your question is not clear but if you can explain yourself i would be glad to .  just trying to : ))