Based on the table...
60-20 = 40 small T-shirts were sold
75-10 = 65 medium T-shirts were sold
40-10 = 30 large T-shirts were sold
25-10 = 15 extra-large T-shirts were sold
making a total of 40+65+30+15 = 150 shirts sold
Or we can use the fact that 50 total were unsold, so 200-50 = 150 were sold in total
So we can say...
40/150 = 0.267 = 26.7% of the t-shirts sold were smalls
65/150 = 0.433 = 43.3% of the t-shirts sold were mediums
30/150 = 0.20 = 20% of the t-shirts sold were larges
15/150 = 0.10 = 10% of the t-shirts sold were extra-larges
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The manager wants to order 240 shirts this time
If the percentages of each t-shirt category stay the same, then we multiply the decimal forms of those percentages above by the new grand total
Small: 240*0.267 = 64.08 which rounds to 64
So the manager should order 64 small shirts
Medium: 240*0.433 = 103.92 which rounds to 104
The manager should order 104 medium shirts
Large: 240*0.20 = 48
The manager should order 48 large shirts
Extra-Large: 240*0.10 = 24
The manager should order 24 extra-large shirts