Q19 of 76 Page 5

Find the cubes of the following numbers by column method:

(i) 35


(ii) 56


(iii) 72

(i) 35


we have , a = 3 and b = 5


































Column I




Column II




Column III




Column IV












+15



+23



+12



12





15



23




42



8



7



5



Thus cube of 35 is 42875.


(ii) 56


we have , a = 5 and b = 6


































Column I




Column II




Column III




Column IV












+50



+56



+21



21





50



56




175



6



1



6



Thus cube of 56 is 175616.


(iii) 72


we have , a = 7 and b = 2


































Column I




Column II




Column III




Column IV












+30



+8



+0







30



8




373



2



4



8



Thus cube of 72 is 373248.


More from this chapter

All 76 →
17

Evaluate the following:

(i)


(ii)

18

Write the units digit of the cube of each of the following numbers:

31, 109, 388, 4276, 5922, 77774, 44447, 125125125

 20

Which of the following numbers are not perfect cubes?

(i) 64


(ii) 216


(iii) 243


(iv) 1728

 21

For each of the non-pefectcubbes in Q. No 20 find the smallest number by which it must be

(a) Multiplied so that the product is a perfect cube.


(b) Divided so that the quotient is a perfect cube.