By what rational number $\frac{-15}{28}$ should be divided to obtain $\frac{3}{4}$?

 How many pieces each of length $15\frac{1}{10}cm$, can be cut from a ribbon of length $181\frac{1}{5} m$?

If $22$ dresses of equal size can be stitched from $71 m$ of cloth, what is the length of cloth required for each dress?

Tarun runs $\frac{5}{2} km$ in $\frac{3}{4}$hour. Find his speed in $km per hour$.

The adjacent figure shows a cutting board on which $30 cm$ long and $2\frac{1}{4}cm$ wide wooden strips are placed side by side and pasted so as to cover it completely. If the width of the wooden board is $22\frac{1}{2} cm$, find the number of wooden strips needed.

$-3$ can be written in the form $\frac{p}{q}$ as

The rational number that is not positive is