Question 164144
F(t) = 500 + 90 * log3(2t + 1)


for t = 40
F(40) = 500 + 90*log3(2*40 + 1)
= 500 + 90 * log3(80 + 1)
= 500 + 90 * log3(81)
= 500 + 90 * log3(3^4)
= 500 + 90 * 4 * log3(3)
= 500 + 90 * 4 * 1
= 500 + 360
= 860 (a)