What is the relation between partial pressure and concentration?
MATHEMATICALLY

At point A

The pressure according to ideal gas equation is $P_A = C_ART_A$. Here $C_A (= n/V)$ is concentration at A.

At point B

Similarly, the pressure according to ideal gas equation is $P_B = C_BRT_B$. Here again $C_B$ is concentration at B.

Now, $P_A$ > $P_B$

So, $C_ART_A$ > $C_BRT_B$

i.e. $C_A/C_B$  > $T_B/T_A$  .....equation 1

Now as the condition is that concentration at A is lower than the the concentration at B. Therefore we can say that 

$C_A/C_B$ &lt; $1$ .....equation 2

Now from equation 1 and 2 we have

$T_B/T_A$ &lt; $1$

which gives us $T_A$ > $T_B$

So in the end, yes, your book was right. It is possible if the temperature at A is more than that at B.

"HOW TO FIND IT IN SECONDS" or "I HATE TO DERIVE BY USING EQUATIONS"

Think of two containers A and B which are connected by a pipe. Both are connected with the help of a pipe which is closed (i.e. it doesn't let the gases exchange). Now we know that concentration of gas in A is lower than the the concentration of gas in B. If we want more pressure of gas in A then the velocity of its particles should be more. Now it is possible if it has more thermal energy. So the temperature should be more in A.