To find the number of tickets sold on Saturday, we start with the information that the ticket sales on Saturday were 175 percent of the ticket sales on Friday.
First, we need to calculate 175 percent of the tickets sold on Friday. Since 400 tickets were sold on Friday, we can calculate this as follows:
\[ \text{Tickets sold on Saturday} = 175% \times 400 \]
To convert 175 percent to a decimal, we divide by 100:
\[ 175% = 1.75 \]
Now, we can multiply:
\[ \text{Tickets sold on Saturday} = 1.75 \times 400 \]
Calculating the multiplication:
\[ 1.75 \times 400 = 700 \]
Therefore, the number of tickets sold on Saturday is
\[ \boxed{700} \]