How many minutes does it take light from the sun to reach earth? (the distance from the sun to earth is 93 million mi; the speed of light is 2.99792458 x 10^8 m/s.)

Achemistry student weighs out 0.306 g of citric acid (h3c6h5o7), a triprotic acid, into a 250 ml volumetric flask and dilutes to the mark with distilled water. he plans to titrate the acid with 0.1000 m naoh solution. calculate the volume of naoh solution the student will need to add to reach the final equivalence point. be sure your answer has the correct number of significant digits.