If –2<a<11 and 3<b<12, then which of the following is NOT true?

(A) 1<a+b<23

(B) -14<a-b<8

(C) -7<b-a<14

(D) 1<b+a<23

(E) -24<ab<132

If we work with the two inequalities we subtract the max of 2nd from min of 1st hence subtracting 11 from 3 gives us –8.

Hence ineq. Should be –8<b-a<14.

Answer (C).

(A) 1<a+b<23

(B) -14<a-b<8

(C) -7<b-a<14

(D) 1<b+a<23

(E) -24<ab<132

If we work with the two inequalities we subtract the max of 2nd from min of 1st hence subtracting 11 from 3 gives us –8.

Hence ineq. Should be –8<b-a<14.

Answer (C).