Me which answer correctly inserts grouping symbols so this expression has a value of 25? 12 - 7 + 2 • 4 + 6 a. (12 - 7) + 2 • (4 + 6) b. (12 - 7 + 2) • (4 + 6) c. (12 - 7) + (2 • 4 + 6) d. 12 - (7 + 2) • (4 + 6)

The distance of a chord from the centre of a circle is 12cm and the lenght of the chord is 10cm. find the radius of the circle

How many kilograms of a 5% salt solution and how many kilograms of a 15% salt solution must be mixed together to make 45kg of an 8% salt solution?

Scores on a university exam are normally distributed with a mean of 78 and a standard deviation of 8. the professor teaching the class declares that a score of 70 or higher is required for a grade of at least “c.” using the 68-95-99.7 rule, what percentage of students failed to earn a grade of at least “c”?