1) E(14) + B(9)= 23, 23- A(7)= 16.

--> The answer is D, as D= 16.

2) D(4) + C(16)= 20, 20 - B(11)= 9.

--> The answer is A, as A= 9.

3) D(17) - B(12)= 5, 5 + A(4)= 9.

--> The answer is C, as C= 9.

4) E(11) + A(6)= 17, 17 - D(7) = 10.

--> The answer is B, as B= 10.

5) C(18) - D(7)= 11, 11 + B(6)= 17.

--> The answer is E, as E= 17.

6) A(23) + B(4)= 27, 27 - C(16)= 11.

--> The answer is D, as D= 11.

7) D(31) - A(17)= 14, 14 + E(12)= 26.

--> The answer is C, as C = 26.

8) B(43) + D(29) =72, 72 - A(18)= 54.

--> The answer is E, as E = 54.

9) A(28) - C(9) =19, 19 + E(5)= 24.

--> The answer is B, as B = 24.

10) C(19) +E(17) = 36 - B(16)= 20.

-->The answer is D, as D = 20.