Aptitude Discussion

Q. |
When the index of an exponential expression with a positive base is doubled, then the expression increases by $700%$. If one of the values that the base cannot have is $X$ which of the following is not a possible value of $P$? |

✖ A. |
4 |

✖ B. |
8 |

✖ C. |
5 |

✔ D. |
1 |

**Solution:**

Option(**D**) is correct

Let the expression be $a^n$

\(\Rightarrow a^{2n}=8a^n\)

\(\Rightarrow n=\log_a8\)

$a$ can be 5, 4 and 8 but it cannot be 1

**Ravi**

*()
*

Can somebody provide a simpler explanation