maths
posted by joel needs help urgently .
30% of the tshirts on a shelf are small. 40% of the remainder are large and the rest are medium. There are 240 more meduium than small tshirts. How many tshirts are there altogether?

t = s+m+l
m = s+240
s = .3t
l = .4(.7t)
small: 600
medium: 840
large: 560
total: 2000
check:30% of 2000 = 600
40% of (2000600) = 560
840 = 600 + 240