Page 151 - NUMINO Challenge_C2
P. 151
Answer
Key
Rank Country France China Korea Italy 2 If Sean is in the 2nd grade:
1st
2nd Sean: 2nd grade ( ), Josh: 3rd grade ( )
3rd Kate: 4th grade ( ), Josh: 2nd grade ( )
4th Beth 2nd grade ( ), Kate: 3rd grade ( )
Beth: 4th grade ( ), Sean: 1st grade ( )
2 If you assume that Jim's prediction of Italy in the
1st place is true, then his prediction of Korea in Kate and Beth are both in the 4th grade;
the 2nd place is wrong. Also, Ryan's prediction of therefore, there is a contradiction.
France in the 1st place will be wrong, but his If Josh is in the 3rd grade:
prediction of China in the 3rd place will be true. Sean: 2nd grade( ), Josh: 3rd grade ( )
In the end, Steven's prediction of China in the Kate: 2nd grade ( ), Josh: 2nd grade ( )
2nd place will be wrong, but his prediction of Beth: 2nd grade ( ), Kate: 3rd grade ( )
Korea in the 4th place will be true. Beth: 4th grade ( ), Sean: 1st grade ( )
Sean: 1st grade, Beth: 2nd grade
Rank Country France China Korea Italy Josh: 3rd grade, Kate: 4th grade
1st Therefore, Kate is in the 4th grade.
2nd
3rd Type 6-2 Road Signs p.54~p.55
4th
1 Assume that road A leads to the treasure, find
3 1st place-Italy, 2nd place-France whether each road sign is true or false.
3rd place-China, 4th place-Korea If road A leads to the treasure, then the road
signs A and B are both true; therefore, there is a
Problem solving contradiction.
Therefore, road A does not lead to the treasure.
1 If the statement of A is 3rd is true:
Road Sign A Road Sign B Road Sign C
A: 3rd ( ), C: 1st ( ) Road A leads
A: 1st ( ), B: 3rd ( )
B: 3rd ( ), C: 2nd ( ) to the
A and B are both in the 2nd place; therefore, treasure.
there is a contraction.
If the statement of C is 1st is true: 2 Assume that road B leads to the treasure, find
A: 3rd ( ), C: 1st ( ) whether each road sign is true or false.
A: 1st ( ), B: 3rd ( ) If road B leads to the treasure then only road sign B
B: 3rd ( ), C: 2nd ( ) is true. Therefore, there is logically no contradiction.
A: 2nd, B: 3rd, and C: 1st; therefore, the Therefore, road B leads to the treasure.
statement is logically true.
Road Sign A Road Sign B Road Sign C
Road B leads
to the
treasure.
3 If road C leads to the treasure, then road signs A and
C are both true; therefore, there is a contradiction.
Road Sign A Road Sign B Road Sign C
Road C leads
to the
treasure.
NUMINO Challenge C2
Key
Rank Country France China Korea Italy 2 If Sean is in the 2nd grade:
1st
2nd Sean: 2nd grade ( ), Josh: 3rd grade ( )
3rd Kate: 4th grade ( ), Josh: 2nd grade ( )
4th Beth 2nd grade ( ), Kate: 3rd grade ( )
Beth: 4th grade ( ), Sean: 1st grade ( )
2 If you assume that Jim's prediction of Italy in the
1st place is true, then his prediction of Korea in Kate and Beth are both in the 4th grade;
the 2nd place is wrong. Also, Ryan's prediction of therefore, there is a contradiction.
France in the 1st place will be wrong, but his If Josh is in the 3rd grade:
prediction of China in the 3rd place will be true. Sean: 2nd grade( ), Josh: 3rd grade ( )
In the end, Steven's prediction of China in the Kate: 2nd grade ( ), Josh: 2nd grade ( )
2nd place will be wrong, but his prediction of Beth: 2nd grade ( ), Kate: 3rd grade ( )
Korea in the 4th place will be true. Beth: 4th grade ( ), Sean: 1st grade ( )
Sean: 1st grade, Beth: 2nd grade
Rank Country France China Korea Italy Josh: 3rd grade, Kate: 4th grade
1st Therefore, Kate is in the 4th grade.
2nd
3rd Type 6-2 Road Signs p.54~p.55
4th
1 Assume that road A leads to the treasure, find
3 1st place-Italy, 2nd place-France whether each road sign is true or false.
3rd place-China, 4th place-Korea If road A leads to the treasure, then the road
signs A and B are both true; therefore, there is a
Problem solving contradiction.
Therefore, road A does not lead to the treasure.
1 If the statement of A is 3rd is true:
Road Sign A Road Sign B Road Sign C
A: 3rd ( ), C: 1st ( ) Road A leads
A: 1st ( ), B: 3rd ( )
B: 3rd ( ), C: 2nd ( ) to the
A and B are both in the 2nd place; therefore, treasure.
there is a contraction.
If the statement of C is 1st is true: 2 Assume that road B leads to the treasure, find
A: 3rd ( ), C: 1st ( ) whether each road sign is true or false.
A: 1st ( ), B: 3rd ( ) If road B leads to the treasure then only road sign B
B: 3rd ( ), C: 2nd ( ) is true. Therefore, there is logically no contradiction.
A: 2nd, B: 3rd, and C: 1st; therefore, the Therefore, road B leads to the treasure.
statement is logically true.
Road Sign A Road Sign B Road Sign C
Road B leads
to the
treasure.
3 If road C leads to the treasure, then road signs A and
C are both true; therefore, there is a contradiction.
Road Sign A Road Sign B Road Sign C
Road C leads
to the
treasure.
NUMINO Challenge C2
