Number System If (83)² is subtracted from the square of a number, the answer so obtained is 8487. What is the number ? 179 163 124 146 179 163 124 146 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x Therefore, x² - (83)² = 8487x² = 8487 + (83)²x² = 8487 + 6889x² = 15376Therefore, x² = 15376 x = 124
Number System Find the number which multiplied by 15 is increased by 196. 26 28 14 20 26 28 14 20 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x. Then,15x - x = 196x = 14
Number System I. 3x2-14x + 8 = 0 II. 2y2 - 1 7 y + 36 = 0 if x >= y if x > y if x <= y if x < y if x >= y if x > y if x <= y if x < y ANSWER EXPLANATION DOWNLOAD EXAMIANS APP l. 3x2 - 12x - 2x + 8 = 0or 3x(x - 4) -2 (x -4) = 0∴ x = 4, 2/3ll. 2y2 - 8y - 9y + 36 = 0or 2y (y - 4) -9 (y - 4) = 0or (2y - 9) (y - 4) = 0∴ y = 4, 9/2
Number System 4/6 of 6/5 of 5/7 of a number is 96. Find the number. 170 164 168 162 170 164 168 162 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x.∴ x x 4/6 x 6/5 x 5/7 = 96∴ x = 96 x 6 x 5 x 7/4 x 6 x 5 = 168
Number System In how many ways can 5 boys be chosen from 6 boys and 4 girls so as to include exactly one girl ? 56 60 54 58 56 60 54 58 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP One girl can be chosen in 4C1 = 4 ways and 4 boys can be chosen in 6C4 = 15 ways ∴ Total number of ways = 4 x 15 = 60 ways.
Number System In a 150-litre mixture of milk and water, the percentage of milk is 84%. How much water should be added so that the percentage of milk becomes 52.5% ? 95 litre 80 litre 90 litre 85 litre 95 litre 80 litre 90 litre 85 litre ANSWER EXPLANATION DOWNLOAD EXAMIANS APP In 150 litre, milk is 84%ie 150 x 84/100 = 126 litre Let us add x litres of waterTherefore, the quantity of mixture = 150 + x∴ 52.5% of (150 + x) = 126 litres 150 + x = 126x100/52.5 = 240 litres∴ x = 240 - 150 = 90 litres
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