5 : 5, 10, 15, 20, 25
6 : 6, 12, 18, 24, 30
3/4 is 75%
for this think of them as quarters 4 quarters is 100 %, 2 quarters is 50% so 3 quarters would be 75%
or you could just do 3 divided by 4 then times that by 100
Atmospheric pressure = 101,325 Newtons / m²
Weight per meter square = 101,325 Newtons
Mass per meter square = 101,325 / (9.81 x 1000)
Mass per meter square = 10.3 tonnes per m²