What is the value of r

Estimate the product. round the first factor to the nearest whole number, round the second factor to the nearest ten, and then multiply. 3 8/9 × 96

Find the length of cu, the triangles are similar.

Ricardo ran the 400 meter race 3 times his fastest time was 54.3 seconds his slowest time was 56.1 seconds if his average time was 55.0 seconds what was his time for the third race