$8.88 \times 88.8 \times 88 = ?$

If $x^{3}+3x^{2}+3x=7,$ then $x$ is equal to

$A$ tin of oil was $\frac{4}{5}$ full when $6$ bottles of oil were taken out. Again,$4$ bottles of oil were poured into it,and it became $\frac{3}{4}$ full. How many bottles of oil can the tin contain?

What is the unit digit of $(217)^{413} \times (819)^{547} \times (414)^{624} \times (342)^{812} ?$

If the difference between $\frac{4}{5}$ part and $\frac{3}{4}$ part of a number is $4,$ what is the number?

$3640 \div 14 \times 16 + 340 = ?$