Number System In how many different ways can the letters of word 'BIOLOGY' be arranged ? 2520 2410 2367 2678 2520 2410 2367 2678 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP In BIOLOGY total 7 letters are there but O comes twice.∴ Number of arrangements = 7!/2! = 2520
Number System What is the value of ? in the following equations ? 72/? = ?/50 40 60 100 80 40 60 100 80 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP (?)² = 72 x 50= (6 x 6 x 2) x (5 x 5 x 2)= (6 x 5 x 2)² = (60)²∴ ? = 60
Number System What should come in place of the question mark (?) in the following number series ? 888 888 444 148 ? 7.4 29 37 33 35 29 37 33 35 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 888 ÷ 1 = 888888 ÷ 2 = 444444 ÷ 3 = 148148 ÷ 4 = 3737 ÷ 5 = 7.4
Number System 4550 ÷ 25% of ? = 130 130 140 135 125 130 140 135 125 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 4550 ÷ ? x 25/100 = 130= 4550 ÷ ?/4 = 130= 4550 x 4/? = 130= ? x 130 = 4550 x 4= ? = 4550 x 4/130 = 140
Number System The sum of the two digits of a two-digit number is 15 and the difference between the two digits of the two digit number is 3. What is the product of the two digits of the two digit number ? 54 None of these 36 14 54 None of these 36 14 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the number be 10 x + yWhere x > yAccording to the question,x + y = 15 and x - y = 3Solving both the equations,x = 9, y = 6∴ x x y = 9 x 6 = 54
Number System The sum of the present age of a father and a son is 60 years. Five years before, the age of the father was four times that of son. What is the present age of the son ? 15 years 18 years 21 years 25 years 15 years 18 years 21 years 25 years ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the father's age be x and son's age yTherefore, x + y = 60 ....................(i)Five years back, (x - 5) = 4 (y - 5)x - 4y = - 15 ......................(2)Solving (1) and (2), x = 45 and y = 15
EXAMIANS