Use the information you are given. We know the total amount of tickets sold was 340 and that 95 of them were child tickets. If you subtract this, you’re left with 245. It now says the number of senior tickets was less than the child tickets so as a maximum that amount would be 94. 245-94=151 and that’s your final answer
1 kilometer is equal to 1000 meters. 4000 meters is 4 times larger than 1000 meters, so 4000 meters in kilometers is going to be 4*1, which is 4 km.
