Question :  If $x^2+\frac{1}{x^2}=7$, then what is the value of $x^3+\frac{1}{x^3}$?

Question : A trader allows a 40% discount on his goods, but he loses 30% on them. Find the percentage of the marked price above the cost price.

Question : The value of $3\frac{1}{2} - [2\frac{1}{4}+ 1\frac{1}{4} - \frac{1}{2}(1\frac{1}{2}-\frac{1}{3} -\frac{1}{6})]$ is:

Question : 30 women working 5 hours a day can complete a work in 18 days, In how many days will 21 women working 8 hours a day complete the same work?

Question : What is the value of $\frac{15 \div 5 \times 3-12 \times 12 \div 6+15 \div 5 \times 6}{18 \div 3 \times 5-12 \div 6 \times 5+18 \div 9 \times 5} ?$