TIMO Khối 7 – Vòng Quốc gia (Heat Round) – Đề số 3

There are 5 pieces of white chopsticks, 7 pieces of yellow chopsticks and 9 pieces of blue chopsticks mixed together. If you want to get 3 pairs of chopsticks with same colours in the dark, at least how many pieces of chopsticks are needed to be taken?

Pieces: Chiếc; Pairs: Đôi/cặp; Same colour: Màu giống nhau; At least: Ít nhất.

Robert goes east for 21km, then goes south for 28km. How many km is he now from the original position?

East: Phía Đông; South: Phía Nam; Original position: Vị trí ban đầu.

Given that : 3 : 7 A B = , : 5 :11 B C = , : 2 : 3 C D = and A B C D + + + = . What is the value of B?

Value: Giá trị