Atrain leaves new york for boston, 200 miles away, at 4: 00 p. m. and averages 75 mph. another train leaves boston for new york on an adjacent set of tracks at 5: 00 p. m. and averages 40 mph. at what time will the trains meet? (round to the nearest minute.)

Aswimming pool has an input pump for filling the pool and an output pump for emptying the pool. the input pump can fill the pool in 3 hours, and the output pump can drain the pool in 5 hours. as you go to bed, the pool is full, but a neighbor’s kid turns on the output pump. at midnight, you awake to find the pool half empty. immediately, you turn on the input pump, but you are sleepy and forget to turn off the output pump. at what time will the pool become full?

Jada has a meal in a restaurant she adds up the prices listed on the menu for everything they ordered and gets a subtotal of $42.00. when the check comes, it says they also need to pay $3.99 in sales tax. what percentage of the subtotal is the sales tax

Having a hard time understanding this question (see attachment).