T 7:00am, an armed van left city A and traveled at 70 km/hr tward city B. At 11:00am, a helicopter headed towards the van, left city B and traveled 110 km/hr. At approximately what time did the helicopter reach the van if the cities are 550 km apart. DUE IN 2 DAYS PLS HELP

Ascientist has 50 grams of a radioactive element. the amount of radioactive element remaining after t days can be determined using the equation (1) after two days the scientist receives a second shipment of 50 grams of the same element. the equation used to represent the amount of shipment 2 remaining after t days is 10) - 50 which of the following is an equivalent form of the expression for the amount remaining in shipment 2? what’s the answer?