Question

A radioactive substance has a half-life of four months. Three-fourths of the substance will decay in-

• A. Three months
• B. Four months
• C. Eight months
• D. Twelve months

Answer 1

Answer: (C)

Eight months

Answer 2

= $\frac { 1 } { 4 }$ =

n = 2 = ̃ t = 2 × 4 = 8 months