Math Problem : G.18 Three kinds of fruit for children

There are some children.
When 60 apples was distributed to every child same number as many as possible, six apples remained.
As is in the same as above, when 120 oranges and 75 persimmons were distributed as many as possible, 12 oranges and three persimmons remained.

Find the number of children.

F.7 Questionnaire to 41 students

I took a questionnaire to 41 students.

There were eight students who drunk milk and 28 students who ate bread this morning.

Find the least number and the most number of the student who did not drink milk nor eat bread this morning.

D.24 Got over a pass

I got over a pass after leaving the departure point and went to a certain destination and returned to the departure point through the way to which I came.

At this time it took 6 hours and a half of going and 7 hours and a half of returning.

Find the distance from a departure point to the destination.

The speed of going up the pass is 6 km/h and that of going down is 8 km/h.

There is no flat way on the way.

J.20 Quadrangle and angle

As for the quadrangle ABCD of the figure, the length of the side BC and side CD is equal. 

Find the degree of the angle of X.