SSC
Sample Paper
SSC-CGL TIER - I Sample Test Paper-4
question_answer
The base of a triangular wall is 7 times its height. If the cost of painting the wall at Rs 350 per 100 square meter is Rs 1225, then what is the base length?
A)50 m
B)70 m
C)75 m
D)100 m
Correct Answer:
B
Solution :
Let the height of the triangle be x. Then BC = 7x \[\Rightarrow \]Area of the \[\Delta \]ABC = \[\frac{1}{2}\times 7x\times x\Rightarrow \frac{7}{2}{{x}^{2}}\] Cost of painting the wall at Rs 350 per 100sq. m. = Rs 1225 \[\therefore \] Cost of painting 100m2 = Rs 350 Cost of painting 1 m2 = Rs \[\frac{350}{100}\] \[\therefore \] Cost of painting \[\frac{7}{2}{{x}^{2}}=\frac{350}{100}\times \frac{7}{2}{{x}^{2}}\] \[\frac{350}{100}\times \frac{7}{2}\times {{x}^{2}}=1225\] (Given) \[\Rightarrow \,\,\,\,\,{{x}^{2}}=\frac{1225\times 100\times 2}{350\times 7}\Rightarrow {{x}^{2}}=100\] \[\Rightarrow \] x = 10m \[\therefore \] Base = 7x = 70m