Answer:
247 km3
Step-by-step explanation:
Density =mass /volume
Volume =mass /density
Mass=density * volume
278km3 =2.78*10 5 m3
917 * (2.78*10 5) = 254,926,000
=2.54926 *10 8 kg
(2.54926 * 10 8)/ 1029 kg/m3
=2477414966m3
247.74 km3
2.4774 * 10 2 km3