Grade 2 MMC Eliminations: Answer to some confusing questions

Question:

Given two-digit numbers 10, 13, 16, 17, and 20. How many are the remaining two-digit numbers smaller than 22

Solution:

The remaining two-digit numbers smaller than 22 are 11, 12, 14, 15, 18, 19, and 21. Therefore, the answer to this question is 7. 

Answer: 7

Question:

Which of the numbers 1, 2, 3, 4, 5, 6, 7, 8, and 9 should we remove, so that the sum of the remaining eight numbers would be 41?

Solution:

Since there are remaining 8 numbers, we are only allowed to remove one number from the set of numbers.

If we add 1 to 9, we get a sum of 50.

Subtracting 41 from 50 we get 9. Therefore, the required answer is 9.

Answer: 9

Question:

The sum of three consecutive numbers is an even number. How many of these numbers are odd?

Solution:

Consecutive odd numbers mean number is succession like 1,2,3.

A three consecutive numbers can either have (odd, even, odd) like 1,2,3 or (even, odd, even) like (4,5,6).

Remember: 

Odd+Odd=Even

Even+Even=Even

Odd+Even=Odd

Therefore, if there are three numbers, the configuration of the numbers must be (odd, even, odd). 

odd+even+odd= even

Hence, the number of odd numbers is 2. 

Answer: 2