Subject: General Aptitude · Chapter: Area · Exam: · Marks: · Difficulty:
The cross-section of a canal is trapezium in shape. The canal is 12 m wide at the top and 8 m wide at the bottom. If the area of the cross-section is 840 sq. m, the depth of the canal is
(a)8.75 m
(b)42 m
(c)63 m
(d)84 m
Answer
Answer (as printed): D
Explanation
$\frac{1}{2}$ (sum of parallel sides) × depth = Its area $$\Leftrightarrow \frac{1}{2}(12+8) \times d=840 \Leftrightarrow d=84 \mathrm{m} .$$