Consider the statements:
x: Birds fly
y: The sky is blue
Which of the following statements can
be represented aa x⇔y?
(i) When the sky is blue, the birds fly.
(ii) Either the bird is flying or the sky is blue.
(iii) Birds fly if and only if the sky is blue.
(iv) When birds fly, the sky is blue.
A shop keeper gave a bill to a customer.
The bill was in two digits but was mistakenly
interchanged thereby undercharging the
customer by $45.00. If the sum of the digits is
9, find the actual value of the bill.