Al and Beverly thought of the same number. Al doubled the number and added 15 to the result. He got 51. Beverly did the same operations with their number, but in the reversed order. What did she get?

Beverly got 6.

51-15=36/2=18 18 being the original thought of #.

18-15=3*2=6

Assume the secret number is x.

"Al doubled the number and added 15 to the result. He got 51."

means 2x+15=51

solving for x:

2x+15=51

2x=51-15

2x=36

x=18

"Beverly did the same operations with their number, but in the reversed order." means she first added 15 to the number, then she doubled the result,

that is she performed the operation:

First: x+15

then: 2 (x+15)

since we found x=18, then we have 2 (x+15) = 2 (18+15) = 2*33=66

Answer: 66