6A Challange

Find the number of squares needed to build the 6th figure.

• 26

• 40

• 44

• 50

In the Fibonacci sequence below, from the second number, the next number is found by adding up the two numbers before it. Namely: 1, 1, 2, 3, 5, 8...

How many even number are there before the 100th term?

• 33

• 40

• 52

• 35

A park has five gates. Cindy wants to enter through one gate and to exit through a different one. In how many ways can she enter and exit the park?

There are 9 white, 5 red and 8 green marbles in a box. If you are blindfolded and asked to draw 3 marbles of the same colour. What is the minimum number of marbles that you can draw from the box?

Bob bought some marbles. 25% of the marbles were red, 40% of the remainder were yellow and the rest were blue. If there were 12 yellow marbles, how many blue marbles were there?

• 40

• 28

• 24

• 18

Evaluate

• $\frac{99}{101}$

• $\frac{99}{202}$

• $\frac{100}{101}$

• $\frac{50}{101}$

The net of a cube with numbered faces is shown in the diagram. Alice correctly multiplies the numbers on opposite faces of this cube. What is the sum of three products that Alice get?

In the diagram, the dashed line and the black path form seven equilateral triangles. The length of the black path is 58. What is the length of the dashed line?

Three children go on an 84 km trip. Each can walk at 5 km/h or ride a bicycle at 20 km/h, but they only have two bicycles among them. At any moment, a bicycle can take only one rider. Also, bicycles can safely be left on the roadside. At least how many hours for all three children to finish the trip?

The diagram shows an addition of a three-digit number, a two-digit number and a one-digit number, with a three-digit sum. The same letter stands for the same digit and different letters stand for different digits. A question mark can stand for any digit, including those represented by a letter. What is the maximum value of the sum?