Hàm số f(x) đồng biến trên R có bao nhiêu cặp số nguyên (a;b) thỏa mãn f(4)<=f(a^2+b^2)

This race was first held in 1953 on august 16th. every decade the race finishes with a festival. how many years is this?

The train station clock runs too fast and gains 5 minutes every 10 days. how many minutes and seconds will it have gained at the end of 9 days?

Ling listed all of the factors of a mystery number: 1,2,4,8,16,32 what is the mystery number?