maths please check my answer
posted by Anonymous .
paul orders a pizza. chef carl randomly chooses two different toppings to put on the pizza from the following:~ pepperoni, onion, sausage, mushrooms and anchovies.
if paul does not eat pizza with mushrooms, determine the probablity that paul will not eat the pizza that chef carl made.
is it 1/5????

There are 5!/(2!*3!) = 120/12 = 10 ways of picking two toppings from five. There are 4 twotopping combinations that do have mushrooms.
Therefore the chances of there being mushrooms on the pizza are 2 in 5. 
Given that S is the central atom, draw a Lewis structure of OSF4 in which the formal charges of all atoms are
help ? 
Given that S is the central atom, draw a Lewis structure of OSF4 in which the formal charges of all atoms are
help ? 
Write a Lewis structure of OSF4 in which the formal charges of all atoms are zero

single bonds on all S to F's, double bond on S to O. Then count valence electrons and add appropriately.