Number System The average of 7 numbers is 15, that of the first three is 6 and that of the last three is 23. What is the fourth number? 7 18 13 15 7 18 13 15 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 4th No. = (Total of 7 Nos) - (Total of first three + total of last 3) = (15 x 7) - (6 x 3 + 23 x 3) = 105 - (18 + 69) =105 - 87 = 18
Number System If the sum of five consecutive even numbers A, B, C, D and E is 130, what is the product of A and E ? 720 780 840 660 720 780 840 660 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the consecutive even numbers be A = 2x, B = 2x + 2, C = 2x + 4, D = 2x + 6 and E = 2x + 8= A + B + C + D + E = 130= 10x + 20 = 130∴ x = 130 - 20/10 = 11Therefore, product of A and E= 22 x 30 = 660
Number System What is the value of ? in the following equations ? 72/? = ?/50 80 100 40 60 80 100 40 60 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 Subtracting 30 from a number, the remainder is one fourth of the number. Find the number? 40 45 22 1/2 30 40 45 22 1/2 30 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP 3/4 x = 30 => x = 40
Number System How many numbers up to 300 and 700 are divisible by 2, 3 and 7 both together? 10 11 8 9 10 11 8 9 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP (700 – 300)/42 = 9 22/42 => 9 Numbers
Number System A gardener wants to plant trees in his garden in such a way that the number of trees in each row should be the same. If there are 4 rows or 5 rows or 6 rows, then no tree will be left. Find the least 240 60 120 30 240 60 120 30 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP The least number of trees that are required = LCM(4, 5, 6) = 60.
EXAMIANS