expression evaluation_quiz

[sarthak-mahajan]

defect:
in ques 14 to 18, its not been specified whether answer should be in integer form or character form.
in ques 17 and 18 answer is given in integer form while in ques 15 answer is in character form,
also answer to ques 14 is wrong, actual answer is '3'(character) or 51(integer)
screenshot:

[kt200021]

fixed #174
commit d5fb037