Which number is IRRATIONAL?

Idont get this question can someone me solve it? ** the distance light travels in one second (1 light second) is about 1.86 ×10^5 mi. saturn is about 475 light-seconds from the sun. about how many miles from the sun is saturn..my guess is 8.83* 10^7 you so much

Given f(x)= 9x+1 and g(x)=x^3, choose the expression (f*g)(x)

Find the number of liters in 12.8 gal of gasoline. round to the nearest hundredths