VTMO 2013 — Grade 3 — final

Hung and Son play marbles. Initially they have equal numbers of marbles. Afterwards Son has $10$ more marbles than Hung. How many marbles did Hung lose?

A library has two shelves for Grade $3$. Class $3$ A borrows $\frac13$ of the first shelf’s books, and class $3 B$ borrows $\frac15$ of the second shelf’s books. Each class borrows $30$ books. How many books were originally on the two shelves?

How many pairs of two-digit natural numbers have a difference of $50$?

A father is $33$ and his two children are $3$ and $7$. In how many years will the children’s combined age equal the father’s age?

A division has divisor $9$, quotient $11$ and remainder $8$. How much must be added to the dividend to make the division exact and increase the quotient by $2$?

The father and mother’s ages total $74$. The mother and An’s ages total $43$. The father and An’s ages total $49$.
$a$) How many years older is the father than the mother?
$b$) Find each person’s age.

Son buys $3$ notebooks and $5$ pencils for $81$ thousand dong. Binh buys $3$ notebooks and $7$ pencils for $105$ thousand dong. Find the price of one notebook and one pencil.

A class has $10$ pupils. The teacher has $80$ candies. She gives every girl the same number of candies and has $3$ left. How many boys are there, given that girls outnumber boys?