in the first half he would have swam 1 km. there are 1000m in a km so 1000/200=5 so he swam the first 200 fly, then a 200 breast, then a 200 fly again, then another 200 breast the finish the first 1 km with a 200 fly. so we switched strokes 4 times.
PS i wouldn't recommend doing a 2 km swim fly and breast
Answer : 40,000
Explanation : when multiplying 10 with 4,000 we get
4000 X 10 = 40,000.
As we multiply, using the chart there are 4 thousand present in the row of thousand column. When we multiply that with 10 it gets shifted to left and becomes 40,000.