Railways
Sample Paper
RRBs Assistant Loco Pilot and Technician CBT STAGE-I Sample Paper-30
question_answer
If the slant height of a right pyramid with square base is 4 m and the total slant surface of the pyramid is 12 sq m, then the ratio of total slant surface and area of the base is
A) 12 : 3
B) 16 : 3
C) 24 : 5
D) 32 : 9
Correct Answer:
B
Solution :
Given, total slant surface area =12m2 Slant height = 4 m Now, area of one slant side of prism \[=\frac{12}{4}=3\,\,{{m}^{2}}\] \[\Rightarrow \]\[\frac{1}{2}\times 4\times a=3\,\,\,\,\,\,\,\,\Rightarrow a=\frac{3}{2}\,\,m\] Now, area of base\[={{\text{(Side)}}^{2}}={{\left( \frac{3}{2} \right)}^{2}}=\left( \frac{9}{4} \right)\,\,{{m}^{2}}\] \[\therefore \]Required ratio\[=\frac{12}{9/4}=\frac{12\times 4}{9}=\frac{16}{3}=16:3\]