Set A contains 12 letters and 7 numbers. Set

B

contains 5 letters and 8 numbers. 0 letters and 4 numbers are common to both sets

A

and

B

. Find the number of elements in set

A

or set

B

.\ The number of elements in set

A

or set

B

is

Set A contains 12 letters and 7 numbers. Set B contains 5 letters and 8 numbers. 0 letters and 4 numbers are common to both sets A and B. Find the number of elements in set A or set B. The number of elements in set A or set B is