 
 <translate> Reconstruct a question, answer pair from this explanation: If each of the 20 customers bought 15 marbles, then they bought 20 * 15 = 300 marbles in total from Mr Julien's store. The number of marbles remaining in the store is 400 - 300 = 100 marbles.
 <ibo> Mepụta ajụjụ, zaa di na nwunye site na nkọwa a: Ọ bụrụ na onye ọ bụla n'ime ndị ahịa 20 zụtara 15 marbles, mgbe ahụ ha zụtara 20 * 15 = 300 marbles na mkpokọta site na ụlọ ahịa Mr Julien. Ọnụ ọgụgụ marbles fọdụrụ n'ụlọ ahịa ahụ bụ 400 - 300 = 100 marbles. 