Guys please help!! I’m having trouble with this

(a) calculate the molarity of a solution that contains 0.0345 mol nh4cl in 400 ml of solution. (b) how many moles of hno3 are present in 35.0 ml of a 2.20 m solution of nitric acid? (c) how many milliliters of 1.50 m koh solution are needed to supply 0.125 mil of koh ?

If 1/√5+1/√5+1=p+q√r , find the values of p, q and r

What is the area of the triangle 10 13 12