A scientist is working with two different concentrations of hydrochloric acid (HCl). One bottle is 80%, and the other is 30% HCl. For their experiment they need 1 liter of 60% HCl. How many liters of the 80% solution do they need? How many liters of the 30% solution?

linear pair postulates

2. angles qrt and qst both measures 156 degrees.

step-by-step explanation:  

we have been given a diagram of a circle and we are told that measure of arc qvt is 156 degrees.  

we can see from our given diagram that angle qrt and angle qst subtends to arc qvt.

since we know that angles subtended by the same arc at the circumference are always equal.

by angle subtended by same arc theorem, measure of angle qrt and angle qst will be equal to the measure of arc qvt.

therefore, angles qrt and qst both measures 156 degrees and 2nd statement is the correct choice.