7. Find the result of the addition operation for the following binary numbers:
(i) $(1001)_{2}+(101)_{2}+(1111)_{2}+(111)_{2}=$ ?
(ii) $(101011)_{2}+(10011)_{2}+(1111)_{2}=$ ?
7.
(i) Solution: Since

Therefore, we have
$$(1001)_{2}+(101)_{2}+(1111)_{2}+(111)_{2}=(100100)_{2}$$
(ii) Solution: Since

Therefore, we have
$$(101011)_{2}+(10011)_{2}+(1111)_{2}=(1001101)_{2}$$