51.Promisor not bound to perform, unless reciprocal promise e ready and willing to
perform .-When a contract consists of reciprocal promises to be simultaneously performed, no promisor
need perform his promise unless the promisee is ready and willing to perform his reciprocal promi se.
Illustrations
(a)A and B contract that A shall deliver goods to B t o be paid for by B on delivery.
A need not deliver the goods, unless B is ready and willing to pay for the goods on delivery.
B need not pay for the goods, unless A is ready and willing to deliver them on payment . (b)A and B contract that A shall deliver goods to B at a price to be paid by instalments, the first ins talment to be paid on
delivery.
A need not deliver, unless B is ready and willing to pay the first instalment on del ivery.
B need not pay the first instalment, unless A is ready and willing to deliver the goods on p ayment of the first instalment .