Basic Arithmetic Riddles
What number is twice as large as 9 minus 3?
12 (2 × (9 - 3) = 12)
I am a number that, when divided by 3, gives a quotient of 9 with no remainder. What number am I?
27 (3 × 9 = 27)
What number do you get if you take half of 60 and subtract 5?
25 (60 ÷ 2 - 5 = 25)
A square has a side length of 5 cm. What is its area?
25 square cm (5 × 5 = 25)
I am a number between 1 and 10. When multiplied by 3, I give a number that is 2 less than 20. What number am I?
6 (3 × 6 = 18)
If I am doubled and then decreased by 8, the result is 20. What number am I?
14 ((14 × 2) - 8 = 20)
I am a number that, when multiplied by 5 and then divided by 3, gives a result of 25. What number am I?
15 (15 × 5 = 75; 75 ÷ 3 = 25)
I am a number that, when doubled and then reduced by 12, equals 24. What number am I?
18 ((18 × 2) - 12 = 24)
I am a prime number that when divided by 5 gives a remainder of 3. What number between 10 and 20 am I?
13 (13 ÷ 5 gives a remainder of 3)
I am a number less than 100. If you divide me by 4, the result is 7 with a remainder of 2. What number am I?
30 (30 ÷ 4 = 7 remainder 2)
Add me to 30 and divide the sum by 5 to get 8. What number am I?
10 (8 × 5 - 30 = 10)
If x is a number and 3x - 7 = 11, what is x?
6 ((11 + 7) ÷ 3 = 6)
If you add me to myself and then subtract 8, you get 6. What number am I?
7 (2 × 7 - 8 = 6)
When you subtract 15 from me and then divide by 5, you get 4. What number am I?
35 ((35 - 15) ÷ 5 = 4)
You subtract 14 from a number and then divide by 7 to get 6. What is the number?
56 (7 × 6 + 14 = 56)
What is the value of x if 2x + 8 = 20?
6 (20 - 8 = 12; 12 ÷ 2 = 6)
Subtracting 7 from me leaves you with a number that is half of 12. What number am I?
13 (12 ÷ 2 + 7 = 13)
Add me to 50 and you get a total that is twice as much as 40. What number am I?
30 (2 × 40 - 50 = 30)
When you subtract 9 from me and divide the result by 3, you get 8. What number am I?
33 ((33 - 9) ÷ 3 = 8)
The sum of three consecutive integers is 51. What is the middle integer?
Answer: 17 (51 ÷ 3 = 17