I came across this question in one of my practice exams using the GMAT prep software, and not sure how the answer is derived... I'll have to write it out in prose form as I'm not sure how to make the radical symbol here..
If M= square root (4) + cube root (4) + 4th root (4), then the value of M is :
a. less than 3
b. equal to 3
c. between 3 and 4
d. equal to 4
e. greater than 4
GMAT Forum
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- Harish Dorai
The best way to solve this is "Divide and Conquer" :-)
1) Square Root of 4 = 2.
2) Cube Root of 4 - Cube of 1 is 1 and Cube of 2 is 8. Since 4 is between 1 and 8, the cube root of 4 should be a decimal number between 1 and 2. Call it 1.x
3) 4th root of 4 - 4th root of 1 is 1 and 4th root of 2 is 16. Since 4 is between 1 and 16, the 4th root of 4 should be a decimal between 1 and 2. call it 1.y
So if you add 2 + 1.x + 1.y which will be 4.z (Something greater than 4).
So the answer choice is E.
1) Square Root of 4 = 2.
2) Cube Root of 4 - Cube of 1 is 1 and Cube of 2 is 8. Since 4 is between 1 and 8, the cube root of 4 should be a decimal number between 1 and 2. Call it 1.x
3) 4th root of 4 - 4th root of 1 is 1 and 4th root of 2 is 16. Since 4 is between 1 and 16, the 4th root of 4 should be a decimal between 1 and 2. call it 1.y
So if you add 2 + 1.x + 1.y which will be 4.z (Something greater than 4).
So the answer choice is E.
2 posts Page 1 of 1