If 30 pens cost ₹750. How many pens will cost ₹1000?​

On a vacation in puerto rico, rose jumped off a cliff into the river in el yunque forest reserve. her heightt as a function of time could be modeled by the fun h(t)=-16t^2 +16t +480, where t is the time after jumping in seconds and h is the height in feet. how many seconds did it take rose to hit the water, round your answer to the nearest hundredth.