Each set has 8 problems with choices A–E, one problem per screen. Tap the circled letter of your answer. Use Prev / Next or the number buttons to move.
1st try: 30 sec – 1 min per problem (4 min – 8 min). You can't submit before the minimum time, and your answers are submitted automatically when time runs out.
After the 1st try you only see your score, not which problems are wrong.
2nd try: every problem gets a hint, but you are not told which ones were wrong. Your 1st-try answers stay, so change any you want. Time: 1 min 30 sec to look over everything, plus 30 sec – 1 min for each problem you missed on the 1st try (for example, 2 missed = 2 min 30 sec – 3 min 30 sec).
7 or more correct = PASS. 8 correct = PERFECT. After the set you see your wrong problems and their solutions.
You can pick any set, in any order.
0:00영차! 영차!
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Your pick is saved for next time. Tap the character at the top to change it any time.