Dấu "?" trong lập trình c ý nghĩa là gì

Whats three fourths of 15(this is supposed to be in math but i clicked too fast)

Write pseudocode to represent the logic of a program that allows the user to enter a value. the program multiplies the value by 10 and outputs the result.

An environmental protection agency study of 12 automobiles revealed a correlation of 0.47 between engine size and emissions. at 0.01 significance level, can we conclude that there is a positive association between the variables? what is the p value? interpret.