VTMO 2026 - Grade 3 - Semifinal - SET 3 - Self-study

The sum of the ages of An, Bình and Châu is now 24 years. In how many years will the sum of their ages be 30 years?

An plays the maze game shown. To win, he must enter at A and leave at B. If he reaches a dead end such as C, he must return to the starting point and this counts as one loss. At least how many losses must he allow for to be certain of eventually winning?

Nam picks oranges and pomelos. The number of oranges is three times the number of pomelos. Which number could be the total number of fruits he picked?

The scale is balanced. One rectangular bar has the same mass as how many circles?

Long places 10 black marbles in a circle. He then places one white marble between each pair of neighboring black marbles. Finally, he places one blue marble between each neighboring black and white marble. How many blue marbles are there?

Two bags contain rice. The first bag has 20 kg more than the second. How many kilograms must be moved from the first bag to the second to make their amounts equal?

Teacher Tom writes the natural numbers from 1 to 100. Jerry erases every number containing the digit 3. What is the sum of the erased numbers?

What is the greatest possible number of intersection points of a circle and a triangle?

What is the greatest number of Sundays a year can have?

Tom joins 25 small squares to make a $5\times5$ square. Jerry removes some small squares, leaving the figure shown. How many squares did Jerry remove?

The natural numbers from 1 to 2017 are arranged in columns A, B, C, D, E, F, G as shown, reversing direction on each successive row. In which column is 2017?

Five boys make these statements.
A: “B tells the truth.”
B: “C lies.”
C: “D tells the truth.”
D: “E lies.”
E: “I tell the truth.”
Given that E’s statement is false, how many boys make true statements?

Khánh puts one banknote into a piggy bank on each of 10 occasions. The possible denominations are 1, 2, 5, 10 and 20 thousand đồng, and every denomination is used at least once. A 5-thousand-đồng note is used on exactly 3 occasions. The 10-thousand-đồng note is used more often than each other denomination. How much does Khánh deposit in total, in thousands of đồng?

Four black boxes and four white boxes are arranged as shown. In one move, An swaps any two boxes. What is the minimum number of moves needed to make the colors alternate?

An empty bottle has a mass of 250 grams. When filled with water, its mass is 480 grams. How many grams of water does the bottle hold?

There are 8 embroidered flowers along each side of a square handkerchief, including one flower at each corner. How many different flowers are embroidered along its boundary?

What is the perimeter of the figure shown?

The numbers in the diagram follow a pattern. Find $A+B$.

The figure is made of squares of side length 3 cm. Find its perimeter.

Four pupils discuss what day today is.
A: “Today is Friday.”
B: “Today is not Friday.”
C: “Today is Saturday.”
D: “A, B and C are all wrong.”
Exactly two pupils tell the truth. What day is tomorrow? Enter the specified code: 0001 = Sunday, 0002 = Monday, 0003 = Tuesday, 0004 = Wednesday, 0005 = Thursday, 0006 = Friday, 0007 = Saturday.