# GMAT Question of the Day (Feb 7): Mixture Problem and Critical Reasoning

- Feb 7, 02:00 AM Comments [0]

Math (PS)

If a portion of a half water/half alcohol mix is replaced with 25% alcohol solution, resulting in a 30% alcohol solution, what percentage of the original alcohol was replaced?

(A) 3%
(B) 20%
(C) 66%
(D) 75%
(E) 80%

Question Discussion & Explanation

GMAT Daily Deals
• e-GMAT’s methods help non-natives improve on GMAT Verbal. \$595 total savings @ GMAT Club. Learn more. Save \$595 via GMAT Club!
• Magoosh GMAT - GMAT Prep that's as smart as you are. Save \$325 on Magoosh through GMAT Club. Get up to \$325 off!
• Accepted Free On-Demand Webinar: 7 Steps to a Stronger MBA Application. Free Webinar Available!
• Check out our discounts that are only offered through GMAT Club. Learn more!

Verbal (CR)

Damaged nerves in the spinal cord do not regenerate themselves naturally, nor even under the spur of nerve-growth stimulants. The reason, recently discovered, is the presence of nerve-growth inhibitors in the spinal cord. Antibodies that deactivate those inhibitors have now been developed. Clearly, then, nerve repair will be a standard medical procedure in the foreseeable future.

Which of the following, if true, casts the most serious doubt on the accuracy of the prediction above?

(A) Prevention of the regeneration of damaged nerves is merely a by-product of the main function in the human body of the substances inhibiting nerve growth.
(B) Certain nerve-growth stimulants have similar chemical structures to those of the antibodies against nerve-growth inhibitors.
(C) Nerves in the brain are similar to nerves in the spinal cord in their inability to regenerate themselves naturally.
(D) Researchers have been able to stimulate the growth of nerves not located in the spinal cord by using only nerve-growth stimulants.
(E) Deactivating the substances inhibiting nerve growth for an extended period would require a steady supply of antibodies.

Question Discussion & Explanation

Like these questions? Get the GMAT Club question collection: online at GMAT Club OR on your Kindle OR on your iPhone/iPad

Browse all GMAT Questions of the Day

Subscribe to GMAT Question of the Day: E-mail | RSS