Question

The value of ${20}^{\circ }{25}^{\prime }{30}^{\prime \prime }$ in degree measure is equal to

• A. ${20.325}^{\circ }$
• B. ${20.525}^{\circ }$
• C. ${20.425}^{\circ }$
• D. ${20.545}^{\circ }$

Answer 1

The correct option is C ${20.425}^{\circ }$

Since ${30}^{\prime \prime }={\left(\frac{30}{60}\right)}^{\prime }={\left(\frac{1}{2}\right)}^{\prime }$
Therefore ${25}^{\prime }{30}^{\prime \prime }={25}^{\prime }+{\left(\frac{1}{2}\right)}^{\prime }={\left(\frac{51}{2}\right)}^{\prime }={(\frac{51}{2}\times \frac{1}{60})}^{\circ }={\left(\frac{51}{120}\right)}^{\circ }={0.425}^{\circ }$
Hence ${20}^{\circ }{25}^{\prime }{30}^{\prime \prime }={20}^{\circ }+{0.425}^{\circ }={20.425}^{\circ }$