Find the last digit of 5¹²⁴ + 6¹²¹.

If the average of 10 observations a₁, a₂, a₃ …., a₁₀ is b, then which of the following will be the average of a₁-11, a₂-11, a₃-11, ……, a₁₀-11?

What is the remainder if 2891 is divided by 4?

Mean of 5 observation is 12. One more observation is included and new means becomes 11. The new observation is:-

3 years ago the age of Rishu was 11 years. The ratio of the present age of Rishu and his father is 1:4. What will be his father’s age after 3 years?

Which of the following will completely divide 14,874?

Find the last digit of 9⁸¹ – 4¹⁶.

If a & b = $\left(\right. \frac{a}{2} + 2 b \left.\right)$(b + a). Find (4 & 2) + (2 & 1). 

Solve for (x)

$\frac{3}{11}$of $\frac{5}{7}$of (x) = 63.

The average age of four brothers is 20 years. When the age of their father is included, the average age increases by 20%. Find the age of the father.

Which of the following will be the last digit of 7⁴⁸⁷?

Find the value of (x) in the given expression 250% of x ÷ 250 – 444 = 200

The average of 20 numbers is 227 and the average of other 30 numbers is 120. Find the average of all the numbers taken together.

Find the value of x.

${\left[{\left(3^2\right)}^6\right]}^5=9^x$

Simplify $\frac{{(8+3)}^2-{(8-3)}^2}{24}$