Two sides of a triangle are 9 and 15. Part A; What is the range of possibilities for the length of the third side? Part B: what is the largest possible whole number perimeter?

Need this asap if anyone can i would be very grateful. if you could show workings that would really

The brain volumes (cm cubed) of 50 brains vary from a low of 904 cm cubed to a high of 1488 cm cubed. use the range rule of thumb to estimate the standard deviation s and compare the result to the exact standard deviation of 175.5 cm cubed, assuming the estimate is accurate if it is within 15 cm cubed

Jack did 3/5 of all problems on his weekend homework before sunday. on sunday he solved 1/3 of what was left and the last 4 problems. how many problems were assigned for the weekend?