Answer:
98092718
Explanation:
lets convert cubic yards to cubic meters
1 cubic meter=1.30790290586 cubic yard
there is an estimated amount of about 750,000,000*1.30790290586 cubic yards
750,000,000*1.30790290586= 980927179.395 cubic yards
now each truck can hold 10 cubic yards, so, divide 980927179.395 by 10
980927179.395/10=98092717.9395
round to the greatest whole number (there can't be any sediment left on Mt. Helens)
98092717.9395 to 98092718
we need 98092718 dump trucks to scoop it all up