A blacksmith blends one alloy of silver that is 35% silver and another that is 95% silver. To the nearest ton, how much of the alloy that is 35% silver is needed to make 139 tons of a 70% silver alloy? ​

Astudent must have an average on five test that is greater than it equal to 80% but less than 90% to receive a final grade of b. devon's greades on the first four test were 78% 62% 91% and 80% what range if grades on the fifth test would give him a b in the course? ( assuming the highest grade is 100%)