Area Problems If the radius of a circle is decreased by 50% , find the percentage decrease in its area. 75% 35% 65% 25% 75% 35% 65% 25% ANSWER EXPLANATION DOWNLOAD EXAMIANS APP let original radius = r and new radius = (50/100) r = r/2 original area = ?r 2 and new area = ? r / 2 2 decrease in area = 3 ?r 2 / 4 * 1 ?r 2 *100 = 75%
Area Problems The Number of rounds that a wheel of diameter 7/11 m will make in going 4 km, is? 1000 1700 2000 1500 1000 1700 2000 1500 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Number of round = total distance / circumference of wheel.= (4 x 1000) / ?d= (4 x 1000) / ( 22/7 x 7/11) = 2000
Area Problems A rectangular lawn 55m by 35m has two roads each 4m wide running in the middle of it. One parallel to the length and the other parallel to breadth. The cost of graveling the roads at 75 paise per sq meter is rs.258 rs.158 rs.58 rs.358 rs.258 rs.158 rs.58 rs.358 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP area of cross roads = (55 x 4) + (35 x 4)- (4 x 4) = 344sq m cost of graveling = 344 x (75/100) = Rs. 258
Area Problems Area of a square is 1/2 hectare. The diagonal of the square is? 250 meter 50 meter 100 meter 50? 2 meter 250 meter 50 meter 100 meter 50? 2 meter ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Area = 1/2 hectare = 10000 / 2 m2= 5000 m2Again Area = 1/2 x (Diagonal)2So 1/2 x (Diagonal)2 = 5000m2? Diagonal2= 10000 ? Diagonal = 100
Area Problems If the sides of a squares is increased by 25%, then the area of the squares will be increased by 53.75% 50% 125% 56.25% 53.75% 50% 125% 56.25% ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Required increment = 2a + [a2 / 100] %= 2 x 25 + [(252)/100)] %= 50 + (625/100)% = 56.25%
Area Problems A circle and a square have same area. The ratio of the side of the square and the radius of the circle is? ? : 1 1 : ? ?? : 1 1 : ?? ? : 1 1 : ? ?? : 1 1 : ?? ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ? Area of square = Area of circle ? x2 = ?r2? x/r = ?? = ? ? : 1
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