Number System The sum of the two numbers is 12 and their product is 35. What is the sum of the reciprocals of these numbers? 7/32 1/35 35/8 12/35 7/32 1/35 35/8 12/35 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the numbers be a and b. Then,a + b = 12 and ab = 35.(a + b)/ab = 12/35= (1/b + 1/a) = 12/35Sum of reciprocals of given numbers = 12/35.
Number System 3251 + 587 + 369 - ? = 3007 1200 1300 1375 1250 1200 1300 1375 1250 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let 4207 - x = 3007 Then, x = 4207 - 3007 = 1200
Number System What should come in place of question mark (?) in the following number series ? 7, 176, 480, 1058, 2188, 4426, ? 8881 8882 8888 8884 8881 8882 8888 8884 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Series is (No. + 9²) x 2, (+8²) x 2, (+7²) x 2, (+6²) x 2.......
Number System The product of two natural numbers is 17. Then, the sum of the reciprocals of their squares is: 290/289 289/290 289 1/289 290/289 289/290 289 1/289 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the numbers be a and b. Then,ab = 17, a = 1 and b = 17So, 1/a2 + 1/b2 = (a2 + b2)/a2 b2 = (12 + 172)/(1 * 17)2 = 290/289
Number System The cost of 87 pens and 29 pencils is `783. What is the cost of 90 pens and 30 pencils ? Rs. 800 Rs. 830 Rs. 810 Rs. 820 Rs. 800 Rs. 830 Rs. 810 Rs. 820 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the price of a pen be 'x' and that of pencil be 'y' Then 87x + 29y = 783Multiplying eqn (i) by 30/29 we get (87x) x 30/29 + (29y) 30/29 = 783 x 30/29∴ 90x + 30y = 810
Number System The difference between 8% of a number and 3% of the same number is 39. What is 2.8% of that number ? 21.84 25.84 27.84 24.84 21.84 25.84 27.84 24.84 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be x.∴ x(8 - 3)% = 39x = 3900/5 = 780∴ 2.8% of 780= 780 x 2.8/100 = 21.84
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