IKMC 2027 - Grades 3-4 - Self-study SET 20 - Thematic Batch 3

In Funnyfeet, every man’s left foot is two shoe sizes larger than his right foot, and every woman’s left foot is one size larger. Shoes are sold only in same-size left–right pairs. Friends buy shoes together to save money. After everyone has shoes that fit, exactly one size-36 shoe and one size-45 shoe remain. What is the smallest possible number of friends?

Choose a number from 50 to 59, then insert digit 0 between its two digits. By how much is the new number larger?

A rectangular garden measures 16 m by 20 m. Six congruent grey flower beds are arranged as shown. What is the perimeter of each bed?

Peter counts clockwise through the triangular parts of a square as shown. Which pictured triangle will he reach at 24?

Pipo the clown likes looking at himself in a mirror. Which picture shows his reflection?

Kanga uses grey and white square tiles to make 930 as shown. How many tiles must change colour to make 806?

One pupil is absent sick today. Among those present there are twice as many boys as girls. Which listed number could be the total number of pupils in the class?

A two-digit number is called sweet when it equals the sum of its digit sum and its digit product. For example,89=(8+9)+(8 × 9). Which listed number is sweet?

Hồng and Trà start an online mathematics test at 7:00. The time limit is 2 hours. Hồng finishes at 8:45. Trà takes 1 hour 30 minutes. Who finishes faster, and how many minutes apart do they finish?

Ann, Bob, Cleo, Dido, Eef and Fer each roll a die and obtain different numbers of dots. Ann’s number is twice Bob’s and three times Cleo’s. Dido’s is four times Eef’s. How many dots does Fer obtain?

Dr. Slump loves coconut juice and builds a coconut grinder. Its drive gears are numbered and arranged in two layers as shown.
The lower layer has gears 1,2,3 with 25,20,16 teeth, respectively. Gear 3 shares an axle with gear 4. The upper layer has gears 4,5,6,7 with 8,16,32,7 teeth, respectively. Grinding one coconut requires 4 turns of gear 7. How many coconuts are ground when gear 1 makes 224 turns? Gears on the same axle rotate at the same rate.

Which number belongs in the grey cell of this addition table?

Kate has four flowers with 6,7,8 and 11 petals. Each time she removes one petal from each of three different flowers. After several such moves, she can no longer choose three flowers with petals. What is the smallest possible total number of petals remaining?

How many triangles are in the figure?

Rectangular wooden bars measuring 1 × 2 × 4 cm are to be packed into a 4 × 4 × 4 cm box. What is the greatest number that fit?

Zosia puts smiley faces in some grey cells of the shown grid. Each white cell’s number gives how many neighbouring cells, sharing an edge or a corner, contain a smiley. How many smileys did she draw?

Luisa wants to fold a paper cube, but her sheet contains 7 squares instead of 6, as shown. Which square should she remove so that the remaining sheet folds into a cube?

Fill the square grid using 1,2 and 3 so that every row and every column contains all three numbers. Harry has already entered three numbers. What can he put in the cell marked with a question mark?

Bob folds a square sheet twice as shown, then punches two round holes and opens it. Which of the listed pictures can he make?

Basil colours the letters of KANGAROO, one letter per day. He starts on Wednesday. On which weekday does he colour the last letter?