KA-0073●●○4 points, difficulty 2 of 34 ptLevel 5–6not yet calibratedHow many different four-letter arrangements can be made from the letters of the word MATH, using each letter once?CNT-05Arrangements of a few objectsalso CNT-03
KA-0074●●○4 points, difficulty 2 of 34 ptLevel 5–6not yet calibratedTwo students are chosen from a group of six to represent the class. How many different pairs are possible?CNT-06Selections of a few objectsalso CNT-08
KA-0075●●●5 points, difficulty 3 of 35 ptLevel 5–6not yet calibratedHow many three-digit whole numbers contain at least one digit 7?CNT-09Complementary countingalso CNT-03, NUM-01
KA-0076●●○4 points, difficulty 2 of 34 ptLevel 3–4not yet calibratedIn how many ways can 7 be written as the sum of two different whole numbers bigger than zero? Swapping the order does not make a new way.CNT-04Caseworkalso CNT-01, NUM-03
KA-0077●●●5 points, difficulty 3 of 35 ptLevel 5–6not yet calibratedA box holds 4 red, 5 blue and 6 green balls, mixed up. How many must be taken out without looking to be sure of having 3 of the same colour?CNT-17The pigeonhole principlealso CNT-18
KA-0078●●●5 points, difficulty 3 of 35 ptLevel 5–6not yet calibratedTen different whole numbers, each bigger than zero, add up to 100. What is the largest that the biggest of them can be?CNT-18Extremal / worst-case countingalso LOG-11, NUM-08
KA-0079●○○3 points, difficulty 1 of 33 ptLevel 3–4not yet calibratedWhich of these is true of every rectangle?GEO-06Properties of triangles and quadrilateralsalso GEO-08
KA-0080●●○4 points, difficulty 2 of 34 ptLevel 5–6not yet calibratedAn isosceles triangle has an angle of 100 degrees. How big is each of the other two angles?GEO-06Properties of triangles and quadrilateralsalso GEO-05
KA-0081●●○4 points, difficulty 2 of 34 ptLevel 3–4has a figurenot yet calibratedA solid is built from unit cubes. The two pictures show it from above and from the front. What is the smallest number of cubes it could be made of?GEO-12Views of a solid: top, front, sidealso GEO-13, CNT-14
KA-0082●●●5 points, difficulty 3 of 35 ptLevel 5–6has a figurenot yet calibratedA room is 8 m long, 4 m wide and 2 m high. An ant walks across the floor and the walls from one bottom corner to the far top corner. What is the shortest distance in metres?GEO-17Shortest paths on and around shapesalso GEO-10, GEO-01
KA-0083●○○3 points, difficulty 1 of 33 ptLevel 3–4not yet calibratedA rectangle has a perimeter of 20 cm. One of its sides is 6 cm. What is its area in square centimetres?GEO-01Perimeter and area of rectilinear shapes
KA-0084●●○4 points, difficulty 2 of 34 ptLevel 5–6not yet calibratedA square of side 6 cm is cut along a midline into two identical rectangles. What is the perimeter of one of them?GEO-03Area by dissection and rearrangementalso GEO-01