The student should answer 10 questions out of 13 on condition that he should answer 4 questions at least from first 5 questions . how many ways can he answer?
in advance

answer is 196

Step-by-step explanation:  If the student answers 4 questions from the first five questions he can choose 6 questions from the remaining 8 questions. Therefore number of combinations will be

5C4×8C6=140

If the student answers 5 questions from the first five questions he can choose 5 questions from the remaining 8 questions. Which will be

5C5×8C5=56

Therefore total number of choices= 140+56=196

If u imagine two parallel lines are getting intersected by a transversal

so u can get 86 and its supplementary angle which ultimately will be equal to x
by corresponding angle theorm
x=180-86
x=  94

Pls find attached file for figure