math
posted by wan .
in a class of 38 children,19 play tennis, 21 play squash and 10 play neither sport. (1)how many children play both sports?(2)how many children play only tennis

28 play some sport
19+21both=28
both = 12
tennis only = 1912 = 7 
Isn't 19 + 21 + 40 which is more than the amount of children in the class? Then you add 10 more that don't play it's 50. So how is the class total 38 as implied?

Where did u get the 12 from

there are 4 green marbles,5 blue marbles,and 6 purples marble.
1. What the probability of picking a red marble, not replacing it, then picking a purple marble?