Test Preparation on CDS-Maths

The HCF of two numbers is 98 and theirLCM is 2352. The sum of the numbers maybe

11372
21398
31426
41484

Let the two numbers be 98a and 98b then their sum = 98a + 98b = 98 (a + b) ? their sum is a multiple of 98. ? only (A) option is divisible by 98. ? sum of numbers = 1372

Consider the following statements :

1. To obtain prime numbers less than 121we are to reject all the multiples of 2 35 and 7.

2. Every composite number less than 121is divisible by a prime number less than11.Which of the above statements is/arecorrect?

11 only
22 only
3Both 1 and 2
4Neither 1 and 2

Both the statements given are correct. As 121 is the square of 11. So to obtain prime numbers less than 121 we reject all the multiples of prime numbers less than 11 i.e. 2 3 5 and 7. Similarly every composite number less than 121 is divisible by a prime number less than 11 i.e. 2 3 5 or 7.

What is the HCF of a 2b4 + 2a2b2 and (ab)7 - 4a2b9 ?

1ab
2a2b3
3a2b2
4a3b2

a2b4 + 2a2b2 = a2b2 (b2 + 2) ........(i) and (ab)7 ? 4a2b9 = a7b7 ? 4a2b9 = a2b2 (a5b5 ? 4b7) ......(ii) From Eqs. (i) and (ii) HCF = a2b2

What is the LCM of x2 + 2x - 8 x3 - 4x2 + 4xand x2 + 4x ?

1x (x + 4) (x - 2)2
2x (x + 4) (x - 2)
3x (x + 4) (x + 2)2
4x (x + 4)2 (x - 2)

A can do a piece of work in 4 days and Bcan complete the same work in 12 days.What is the number of days required to dothe same work together?

Consider the following statements :1. x + 3 is the factor of x3 + 2x2 + 3x + 8.2. x - 2 is the factor of x3 + 2x2 + 3x + 8.Which of the statements given above is/arecorrect ?

11 only
22 only
3Both 1 and 2
4Neither 1 nor 2

A person sold an article for ` 3600 and gota profit of 20%. Had he sold the article for` 3150 how much profit would he havegot?

14%
25%
36%
410%

If x + y - 7 = 0 and 3x + y - 13 = 0 thenwhat is 4x2 + y2 + 4xy equal to ?

175
285
391
4100

If the expression x3 + 3x2 + 4x + k has afactor x + 5 then what is the value of k ?

1- 70
270
348
4- 48

10.

In a class of 110 students x students takeboth Mathematics and Statistics 2x + 20 students take Mathematics and 2x + 30 students take Statistics. There are no students who take neither Mathematics norStatistics. What is x equal to ?


Right Ans	Wrong Ans	Not Attempted