IMO Practice Test — Operations with Fractions (Unlike Denominators)
6 Questions • 25 min • Olympiad level
25:00
Question 1 of 6
medium
Which is the greatest: 2/3, 3/4, 5/6?
2/3
3/4
5/6
all equal
Explanation: 5/6 ≈ 0.833 is the largest.
Question 2 of 6
medium
A pizza is cut into eighths. You eat 3/8 and a friend eats 1/4. How much is gone?
5/8
4/12
1/2
4/8
Explanation: 1/4 = 2/8; 3/8 + 2/8 = 5/8.
Question 3 of 6
medium
2/3 − 1/4 = ?
5/12
1/12
1/7
3/12
Explanation: 2/3 = 8/12 and 1/4 = 3/12; 8/12 − 3/12 = 5/12.
Question 4 of 6
hard
Ascending order of 1/2, 2/3, 3/5:
1/2, 3/5, 2/3
3/5, 1/2, 2/3
1/2, 2/3, 3/5
2/3, 3/5, 1/2
Explanation: 0.5 < 0.6 < 0.667 → 1/2, 3/5, 2/3.
Question 5 of 6
hard
1/2 + 2/5 = ?
9/10
3/7
3/10
1
Explanation: 5/10 + 4/10 = 9/10.
Question 6 of 6
hard
A bottle holds 3/4 L. You drink 1/3 L. How much is left?
5/12 L
1/12 L
2/7 L
1/2 L
Explanation: 3/4 = 9/12 and 1/3 = 4/12; 9/12 − 4/12 = 5/12 L.