Please answer these two questions with reason

Which of the following statements is/are true about flash memory?

1. Like DRAM (DRAM could be considered as materials for main memory) flash is a semiconductor memory.

2. Like disks, flash does not lose information if it loses power.

3. NOR flash is less expensive and more popular than NAND flash.

Which of the following statements is/are true about RAID levels 1, 3, 4, 5, and 6?

1. RAID systems rely on redundancy to achieve high availability.

2. RAID 1 (mirroring) has the highest check disk overhead.

3. RAID 1, 3, 4, and 5 are only able to correct 1 disk failure while RAID 6 is able to correct 2 simultaneous failures.