Areas Quiz Set 003

The side = $√{13^2 - 5^2}$ = $√{169 - 25}$ = 12. So the area = 5 × 12 = 60 sq. m.

If x% and y% is the increase in the dimensions, then the area of a rectangle increases by $(x + y + {xy}/100)$% = $(7 + 4 + {7 × 4}/100)$% = ${282/25}$, which is same as: $11{7/25}$%

If the radius of the circle is R, then the side of an inscribed square is $√2 × R$, so the area is 2 × R² = 2 × 8² = 128 sq. m.

If L and B are the length and breadth of the rectangle, then L - B = 68 and 2(L + B) = 168. Solving, we get L = 76 and B = 8, so the area is 76 × 8 = 608 sq. m. TIP: Sometimes long multiplications can be avoided by looking at the units place of the given options.

The area of the ring is equal to the difference of the areas of the two circles. π($18^2 - 15^2$) = 99π sq. cm. The total area is π × 18² = 324π. The probability of hitting the ring is ${99π}/{324π}$ = ${11/36}$.