Mother has 6 identical square cakes. She cuts every cake into the same number of equal pieces so that all the cake can be shared equally among 8 children. What is the smallest possible number of pieces per cake?
An and Bình initially have equal numbers of marbles. An buys 24 more and Bình buys 6 more. Bình then has one third of their combined total. How many marbles did An have at first?
Minh wants to buy a book but is 15,000 đồng short. Khoa wants the same book but is 19,000 đồng short. Together their money is exactly enough for one copy. How much does the book cost?
Four pupils guess their teacher’s age as 24, 29, 35 and 37 years. The teacher says their guesses differ from his true age by 1, 5, 6 and 7 years, in some order. How old is the teacher?
Some pupils stand in a line. Pi is in the exact middle of the line and is also halfway between An and Bình. An is 3rd from the front. Bình is 8 positions after An. How many pupils are in the line?
There are 660 passengers on ships A and B altogether. If 30 passengers move from A to B and 70 move from B to A, the ships then have equal numbers. How many passengers were on each ship at first? Show your working.
An older brother has 6 more candies than his younger brother. Mother gives the older brother 2 more candies and the younger brother 5 more. They then have 31 candies altogether. How many candies did the younger brother have at first?
Mai has the piece of card shown, with equally spaced points marked around its boundary. She makes one straight cut joining two marked points, dividing the card into two pieces with equal perimeters. How many different cuts are possible?
The Fibonacci sequence begins $1,1,2,3,5,8,13,21,34,\ldots$, with each later term the sum of the previous two. How many of its first 100 terms are odd?
Việt writes the positive even numbers less than 102 in increasing order. Dũng writes the positive odd numbers less than 101 in increasing order. In each column, Nam writes the product of Việt’s and Dũng’s numbers, as shown. How many different numbers divisible by 5 have the three boys written altogether? Count each value only once.
Đức has marbles numbered 1, 3, 5, 7, 9. Hải has marbles numbered 0, 2, 4, 6, 8. Nhi takes one marble from each boy and adds their numbers. How many different sums can she obtain?