The local primary school are having their school photographs taken. As there are lots of photographs to take, there are two photographers working in two separate rooms.
Both photographers start work at 9 am.
Photographer 1 takes 3 minutes per person.
Photographer 2 takes 6 minutes per person.
After 35 minutes, how many times will children have gone in to have their photographs taken at the same time?
In 35 minutes, Photographer 1 will have taken 35 / 3 = <<35/3=11.67>>11.67 photographs.
In 35 minutes, Photographer 2 will have taken 35 / 6 = <<35/6=5.83>>5.83 photographs.
Since we cannot have a fraction of a photograph, we can conclude that 11 photographs will have been taken at the same time. Answer: \boxed{11}.
To find out how many times children have gone in to have their photographs taken at the same time, we can calculate the number of children each photographer has taken photos of in 35 minutes.
Photographer 1 takes 3 minutes per person, so in 35 minutes, Photographer 1 can take photos of 35/3 = 11.67 children. Since we cannot have a fraction of a child, we take the whole number part, which is 11.
Photographer 2 takes 6 minutes per person, so in 35 minutes, Photographer 2 can take photos of 35/6 = 5.83 children. Again, we take the whole number part, which is 5.
Therefore, in 35 minutes, Photographer 1 has taken photos of 11 children, and Photographer 2 has taken photos of 5 children.
To find out how many times children have gone in to have their photographs taken at the same time, we need to determine the common multiple of the number of children each photographer has taken photos of.
The common multiple of 11 and 5 is 55 (11 x 5).
Thus, children have gone in to have their photographs taken at the same time 55 times in 35 minutes.