Here is an old brainteaser by the central asian scholar biruni (973−1048). if 10 dirhams (a unit of currency) earn 5 dirhams of profit in 2 months, how much profit will 8 dirhams earn in 3 months?

10 units earn a profit of 5 in 2 months

that means

1 unit earns a profit of 0.5 in 2 months

that means

1 unit earns a profit of 0.25 in 1 month

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8 units earn a profit 8*0.25=2 in 1 month

8 units earn a profit of 3*2=6 in 3 months

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.

idk

step-by-step explanation: