ACT Math Practice Question #1269 (Medium (31)) | Test Citadel
TC
Test Citadel
ACT Math Difficulty: Medium (31)

Digital ACT Math Practice Question #1269

Test your problem-solving accuracy on this official-caliber item. Select an answer choice to check your reasoning instantly.

A sample of Radon-222, commonly utilized as a subterranean geological tracer, exhibits an initial radioactivity of $1600\text{ megabecquerels (MBq)}$. The half-life of Radon-222 is $4\text{ days}$. What is the remaining radioactivity of the sample, in MBq, after exactly $24\text{ days}$ have elapsed?
Select Your Answer:
Socratic AI Engine Step-by-Step Derivation
0ms Precomputed
⚡ 15-Second Desmos Speed Hack

Divide by 2 repeatedly: $1600 \rightarrow 800 \rightarrow 400 \rightarrow 200 \rightarrow 100 \rightarrow 50 \rightarrow 25$. Takes under 10 seconds.

Masterclass Solution & Distractor Trap Analysis

Calculate the number of half-lives elapsed: $n = \frac{\text{Total Time}}{\text{Half-life}} = \frac{24}{4} = 6$. The remaining activity is given by $A = A_0 \left(\frac{1}{2}\right)^n = 1600 \left(\frac{1}{2}\right)^{6} = \frac{1600}{64} = ...

Distractor Analysis: Trap choice eliminates careless test-takers who confuse roots with coordinates...

🔒 Citadel Pro Scholar Vault

Unlock Full Solution & 2,600+ Official Drills

Access detailed Socratic steps, trap breakdowns, authentic timed module simulations, and Desmos speed hacks for just $9.99/mo.

Socratic Assistant

Targeted hints without disclosing final solutions.

I am your Socratic tutor. Click one of the quick guidance buttons above or ask a specific question below about a formula or method.