The suspense account

today, when l was doing the exercises l met such a strange situation
in revision kit
question 18.5
a gas bill(dr)of 420$ had been recorded in the gas account as 240$

here:
the suspense account is created in credit side

but
question 18.7
a cheque(dr) for 19000$ received from a customer was correctly entered in the cash book but was posted to the control account as 9100$

here
the suspense account is created in debit side(according to revision kit)

both are essentially the same but differently resolved
why??