DSE 2011 Question 32: Joint distributions, covariance and correlation

Setup, from Q31 of the paper:

Suppose $X$ and $Y$ are random variables. $X$ takes values $-1$ and $1$; $Y$ takes integer values 1 to 6. The joint distribution has $P(X=-1)$ row $[0.1,\ a,\ 0.3,\ 0,\ 0,\ 0]$ and $P(X=1)$ row $[0,\ 0,\ b,\ 0.1,\ 0.1,\ 0.1]$ across $Y=1,\ldots,6$. It is known that $E(X)=-0.2$ and $E(Y)=3.2$. The value '$a$' in the table equals

(Same joint distribution as the previous question.) The value '$b$' in the table equals