There were 400 visitors at a zoo in the morning the number of visitors increased to 640 in the afternoon what was percentage increase in the number visitors

To calculate the percentage increase in the number of visitors, you can use the following formula:

Percentage Increase = ((New Value - Old Value) / Old Value) x 100

In this case, the old value is 400 (the number of visitors in the morning) and the new value is 640 (the number of visitors in the afternoon).

Percentage Increase = ((640 - 400) / 400) x 100
Percentage Increase = (240 / 400) x 100
Percentage Increase = 0.6 x 100
Percentage Increase = 60%

Therefore, there was a 60% increase in the number of visitors from morning to afternoon.