Twice a certain number is equal to the number the result is 21 Find the number

Janet is mixing a 15% glucose solution with a 35% glucose solution. this mixture produces 35 liters of a 19% glucose solution. how many liters of the 15% solution is januet using in the mixture? a. 25 liters c. 28 liters b. 7 liters d. 10 liters

In the diagram below, dab and dac are adjacent angles. if mdac = 25°, what is mdab in degrees? what is mbac in degrees?

If sr is 4.5cm and tr is 3cm, what is the measure in degrees of angle s?