For every 100 additional people that board a spaceship, its speed is halved. If the speed of the spaceship with 200 people on board is 500km per hour, what is its speed in km/hr when there are 400 people on board? Give the rationale and then the answer.
Let's think step by step. For every addition of 100 people added the speed is halved so for the first 100 people added its speed is 1 / 2 * 500 km / hr = 250 km / hr. For another addition of 100 people its speed is also halved, 1 / 2 * 250 km / hr = 125 km / hr. So for the total of 200 additional people, its speed is 125 km / hr.. The answer is: 125.

On Blacks, Martha goes to the mall to buy clothes on sale. For every 2 jackets she buys, she gets 1 free jacket. For every 3 t-shirts she buys, she gets 1 free t-shirt. Martha decides to buy 4 jackets and 9 t-shirts. How many clothes will she take home? Give the rationale and then the answer.
Let's think step by step. For buying 4 jackets Martha gets 4 jackets / 2 = 2 jackets for free. For buying 9 t - shirts, Martha gets 9 t - shirts / 3 = 3 t - shirts for free. Adding the free jackets, Martha gets 4 jackets + 2 jackets = 6 jackets. Adding the free t - shirts, Martha gets 9 t - shirts + 3 t - shirts = 12 t - shirts. In total, Martha will take home 6 jackets + 12 t - shirts = 18 clothes.. The answer is: 18.

Bryan starts exercising at home during quarantine. To start, he decides to do 3 sets of 15 push-ups each. Near the end of the third set, he gets tired and does 5 fewer push-ups. How many push-ups did he do in total? Give the rationale and then the answer.
Let's think step by step. In total, Bryan would have done 3 sets * 15 push - ups / set = 45 push - ups. Subtracting the push - ups he didn't do in the third set, Bryan did 45 push - ups - 5 push - ups = 40 push - ups.. The answer is: 40.