16. The store released two batches of notebooks. If the second batch had 5 more notebooks than it actually did, the product of the numbers expressing the quantities of notebooks in each batch would have increased by 1250, and if the first batch had 7 more notebooks, then this product would have increased by 3150. How many notebooks in total did the store release?
16. Since increasing the second factor by 5 increases the product by 1250, the first factor is $1250: 5=250$, i.e., in the first batch there were 250 notebooks. When the first factor is increased by 7, the product increases by 3150, so the second factor is: $3150: 7=450$, i.e., in the second batch there were 450 notebooks. Therefore, the store released a total of $250+$ $+450=700$ (notebooks).