Tell which number is prime 19,28,49,63

Can someone pls ! pls answer all. no explanation needed..

Apositive number a or the same number a increased by 50% and then decreased by 50% of the result?

Rob spent 25%, percent more time on his research project than he had planned. he spent an extra h hours on the project. which of the following expressions could represent the number of hours rob actually spent on the project? two answers