Monthly Archives: September 2021

Black stones and white stones are arranged on the table in the following pattern: ⚫◯◯⚫⚫⚫◯⚫⚫◯◯◯⚫◯◯⚫⚫⚫◯⚫⚫◯◯◯⚫◯◯⚫⚫⚫ …… The color of the 999th stone is __________ and there are ____________ white stones among the 999 stones. For the following sequence of numbers: … Continue reading →

The total number of 2-digit positive integers with the ten-digit greater than the unit-digit is __________. The sum of 20 consecutive natural numbers is 2010. The smallest one is __________ and the largest one is __________. The following are rows … Continue reading →

Use symbol $+$, $-$, $\times$ and $\div$ to fill in the blanks to make the following equation: $$ \texttt{1}\ \boxed{　}\ \texttt{2}\ \boxed{　}\ \texttt{3}\ \boxed{　}\ \texttt{4}\ \boxed{　}\ \texttt{5}\ =\ \texttt{20}$$ Find the value of the following: $$9999999+999999+99999+9999+999+99+9$$ Find the value of … Continue reading →