you are told that 1331 is a perfect cube you guess without factorisation what is its cube root? similarly, guess the cube roots of 4913, 12167, 32768.
Answers
Answer:
Answer
1331=we divide 1331 into groups of three digits starting from the right. So 1331 has two groups one is 331 and another is 1.
For first group 331, the digit 1 is at one's place .1 comes at a unit place of a number only when its cube root ends with 1. So one's place of the required cube root is 1.
For another group, i.e.1 1
3
=1 and 2
3
=8 so 1 lies between 0 and 8.the smaller number among 1 and 2 are 1. So the one's place of 1 is 1 and ten's place of cube root 1331 is 1
Hence
3
1331
=11
For 4913
we divide 4913 into groups of three-digit starting from the right. So 4913 has two groups one is 913 and another is 4.
For first group 913, the digit 3 is at one's place .3 comes at a unit place of a number only when its cube root ends in 7. So one's place of the required cube root is 7.
For another group, i.e.1 1
3
=1 and 2
3
=8 so 4 lies between 1 and 8.the smaller number among 1 and 2 are 1. So the one's place of 1 is 1 and ten's place of cube root 4913 is 1
Hence
3
4913
=17
For 12167
we divide 12167 into groups of three-digit starting from the right. So 12167 has two groups one is 167 and another is 12.
For first group 167, the digit 7 is at one's place .7 comes at a unit place of a number only when its cube root ends in 3. So one's place of the required cube root is 3
For another group, i.e.12 2
3
=8 and 3
3
=27 so 12 lies between 8 and 27.the smaller number among 2 and 3 are 2. So the one's place of 2 is 2itself and ten's place of cube root 12167 is 2
Hence
3
12167
=23
For 32768
we divide 32768 into groups of three-digit starting from the right. So 32768 has two groups one is 768 and another is 32.
For first group 768, the digit 8 is at one's place .8 comes at the unit place of a number only when its cube root ends in 2. So one's place of the required cube root is 2.
For another group, i.e.1 3
3
=27 and 4
3
=64 so 32 lies between 27 and 64.the smaller number among 3 and 4 are 4.So the ten's place of cube root 32768 is 3
Hence
3
32768
=32
Answer:
I'm not sure
Explanation: