TRT: Time reversal test requires that the index number computed backward (P10) should be reciprocal of the index number computed time forward (P10)
i.e., P10 = \(\frac{1}{P_{01}};\) Exccept the factor 100.
FRT: Factor reversal test requires that the product of price and quantity index numbers both computed time forward is equal to the total change in the value.
Except the factor 100.