2002 Bar: Does the RTC-Manila have jurisdiction over the case? Explain. (3%)

2002 Bar: P sued A and B in one complaint in the RTC-Manila, the cause of action against A being on an overdue promissory note for P300,000.00 and that against B on an alleged balance of P300,000.00 on the purchase price of goods sold on credit. Does the RTC-Manila have jurisdiction over the case? Explain. (3%)
The answer is in the negative. The RTC-Manila has no jurisdiction over the case. A and B should not be joined as defendants in one complaint because the right to relief against both defendants do not arise out of the same transaction or series of transactions and there is no common question of law or fact common to both (Sec. 6, Rule 3). Therefore, separate complaints will have to be filed and they would fall under the jurisdiction of the Metropolitan Trial Courts (Flores vs. Mallare-Phillips).