You are told that 1,331 is a perfect cube. Can you guess without factorisation what is its cube
root? Similarly, guess the cube roots of 4913; 12167; 32768.
Answers
Answer:
here your answer
Step-by-step explanation:
1331
it lies between 10^3=1000 and
20^3=8000 and it's last digit is 1
can't be the cube of 1 so
cube root of 1331 is 11
similarly
4913
it's lies between
10^3=1000 and 20^3=8000
and it's last digit 3
can't be the last digit of cube so
3√4913=17
12167
it's lies between
20^3=8000 and 30^3=270000
last digit 7
can't be the last digit of cube of but 3
so 3√12167=23
32768
u can proceed above way
u will get answer is 32
Solution:
We know that 10³ = 1000 and Possible cube = 11³ = 1331 Since, cube of units digit 1³ = 1.
Therefore, cube root of 1331 is 11.
4913 :--
We know that 7³ = 343
Nealy number comes with 7 as unit place 17³ = 4913. Hence, cube of 4913 is 17.
12167 :--
We know that 3² = 27
Hence, next number comes with 7 as centre place = 17³ = 2167 and next number with 3 as one's digit 23³ = 12167, Hence cube root of 121667 is 23.
32768 :--
We know that 2³ = 8
Here in cube, one's digit = 8
Now, next number with 2 as one's digit 12³ = 1728
and next number with 2 as one's digit 22³ = 10648 and next number with as one's digit 32³ = 32768.
Therefore, 32768 is 32 cube root.