I am surprised to see these problems on the PSATs. I can't imagine what the SATS will be like.
I did not understand problems 15 and 18. They qualify as 'Hard' questions. Do you think so?
I ransacked my brain, trying to find a solution but my efforts were to no avail. (Pardon the messy work ) The diagram on number 18 included everything except the line of congruencies and the area marked 'x' and 'y'.