a) The trial balance of Nyaguthie enterprises prepared as at 30th  April, 2016 failed to balance. The difference was posted to a  suspense account. On investigation, the following errors were  revealed.

i. Payment of sh 4,900 to Demo had been entered in the  account of Dome.
ii. Purchase of goods sh 49,000 had been entered in the  purchases account as sh 94,000.
iii. Payment for motor expenses sh 12,000 had been  entered in motor vehicles account.
iv. Payment of rent sh 24,000 had only been entered in  the cashbook.
v. Required:
vi. Prepare journal entries to correct the above errors

b) State the merits of maintaining control accounts.