Question

help q 21 and 22

I think the answer for q 22 is 19 but not sure so please also do that
for q 21 really dob't understand it ​

Answer 1

21. when red one is placed in corner then only 3 of its faces can be covered  (as other three form an edge)

therefore 3 orange cubes are placed

now each of the orange cube will have 3 faces covered and rest 3 uncovered

(u can practically do this by taking some matchboxes or imagine the situation)

now 3 faces of 3 cubes =9 faces has to be covered

so 9 blue cubes are required

22. let us understand this first

1/2 > 1/3

and

2 < 3

therefore we can conclude that when we reverse the numerator and denominator the sign of inequality changes

(u can try this practically)

so

5/96 < 1/n < 6/113

or

96/5 > n > 113/6

or

19.2 > n > 18.83

therefore our answer is 18 and 19

hope this helps