Year 8 Brain Teasers Challenge

If you multiply this number by any other number, the answer will always be the same number. What is it?

• 0

• 1

• 10

• -1

What is the next number in the sequence: 2, 6, 12, 20, 30, ...?

• 42

• 40

• 36

• 48

A snail climbs up 3 feet during the day and slips back 2 feet at night. If the well is 30 feet deep, how many days will it take for the snail to get out of the well?

• 28 days

• 27 days

• 29 days

• 30 days

If you have a cube which is 5x5x5, how many cubes are there in total?

• 125

• 150

• 175

• 25

What comes next in the pattern: JFMAMJJASON_?

• D

• J

• M

• A

If it takes 5 machines 5 minutes to make 5 widgets, how long would it take 100 machines to make 100 widgets?

• 100 minutes

• 5 minutes

• 1 minute

• 20 minutes

You have 8 balls of equal size. 7 of them weigh the same, and one of them weighs slightly more. How can you find the ball that is heavier by using a balance and only two weighings?

• Divide the balls into two groups of four, then compare.

• Divide the balls into three groups of three, two, and three, then compare.

• Divide the balls into three groups of two, three, and three, then compare.

• Divide the balls into three groups of two, two, and four, then compare.

What is the smallest square number that is divisible by each of the numbers 1 to 10?

• 900

• 2500

• 3600

• 10000

If you write down all the numbers from 1 to 100, how many times do you write the digit 3?

• 10

• 11

• 20

• 19

A farmer has 17 sheep, and all but 9 die. How many are left?

• 17

• 9

• 8

• 0