If the index number of the current year is computed on the basis of quantities of base year $(P_{01})$ and another index number is computed on the basis of quantities of current year $(P_{10})$ and index numbers satisfy time reversed test, then $P_{01}.P_{10}=$

1

The correct answer is Option (2) → 1

The time-reversed test for index numbers states,

$P_{01}×P_{10}=1$

It is so because to ensure consistence between the two index numbers.