HKIMO 2020 Grade 4 National Final (Heat) Set 01

Andy scored 87 and John scored 72 in a Mathematics exam. If the average score of Andy, John and Mary is 85, what is Mary’s score?

If 18 June 2019 is Tuesday, which day of the week is 23 February 2020?

A bookstore had a box of books. On the first day, it sold 5 fewer books than half of the original number. On the second day, it sold one third of the remaining books and 12 more books. Finally, 20 books were left. How many books were there originally?

According to the pattern shown below, what is the missing number?

There are 108 chickens and rabbits altogether on a farm. They have 336 legs in total. How many chickens are there?

Find the value of $23\times9+26\times17+17\times20+23\times7$.

Find the value of $75\div19+126\div57-6\div38$.

Find the value of $\dfrac{1}{2+\dfrac{3}{4+\frac15}}$. Write the answer in its simplest form.

Find the value of $4+7+10+13+16+\cdots+142+145+148+151$.

A, B and C are different one-digit numbers. Find $A+B+C$ if the displayed multiplication is correct.

How many positive factors does 14508 have?

The 10-digit number $\overline{201920202A}$ is divisible by 9. Find the maximum value of A.

Define $a\otimes b=(a+b)\times(2\times a-b)$. Find $15\otimes(3\otimes2)$.

The sum of positive integers A and B is 1024. A is 7 times B. Find A.

How many 3-digit numbers are divisible by 3 or by 7?

How many rectangles contain the asterisk in the figure below?

How many rectangles are there in the figure below?

A rectangle has perimeter 128 cm and integer side lengths. Find its minimum area in $\mathrm{cm}^2$.

At least how many unit squares can be seen when viewing the figure below from the right?

A prism has 90 vertices. Find the sum of its number of edges and number of faces.