The ratio of sigma and π bonds present in pyrophosphoric acid is

To determine the ratio of sigma and pi bonds in pyrophosphoric acid, we first need to understand the molecular structure of the compound.

Pyrophosphoric acid has the chemical formula ${H}_{4}{P}_{2}{O}_{7}$. The molecule contains two phosphorus atoms, seven oxygen atoms, and four hydrogen atoms.

The structure of pyrophosphoric acid is

It contains total $12$ sigma bonds and $2$ pi bonds. So
$\dfrac{\text{No. of}\sigma\text{bonds}}{\text{No. of}\pi\text{bonds}} = \dfrac{12}{2} = 6: 1$