Tricky math questions that catch people out

Math questions can spark fierce debate at quiz nights, especially when order of operations comes into play. Use them sparingly to add some friendly controversy.

1What is 8 ÷ 2(2 + 2)?

Answer:16 (though 1 is a common wrong answer)(click to reveal)

2What is 6 ÷ 2(1 + 2)?

Answer:9(click to reveal)

3What is 3 + 3 × 3 - 3 + 3?

Answer:12(click to reveal)

4If you have 3 apples and take away 2, how many apples do you have?

Answer:2 (you took them, so you have them)(click to reveal)

5What is 0.1 + 0.2? (Be precise)

Answer:0.3 (accept 0.30000000000000004 for bonus points - that's what computers get)(click to reveal)

6What is 10 - 4 ÷ 2 + 1 × 2?

Answer:10(click to reveal)

7A bat and ball cost £1.10 together. The bat costs £1 more than the ball. How much does the ball cost?

Answer:5p (not 10p!)(click to reveal)

8What is 2² + 2² × 2²?

Answer:20(click to reveal)

9What is the next number in this sequence: 1, 11, 21, 1211, 111221, ?

Answer:312211 (the "look-and-say sequence" - each number describes the previous one)(click to reveal)

10What is 100 ÷ 10 ÷ 2?

Answer:5 (division goes left to right)(click to reveal)