Opening your study page

Loading...

Getting the next screen ready.

Chapter check

Select your answers

0/8 answered

Question 1

Unique prime factorisation

Difficulty: easySource: NCERT Exercise 1.1 alignedTopic: fundamental-theorem-of-arithmetic

Which is the prime factorisation of $3825$ ?

1 $3\times5^2\times17$ 2 $3^2\times5^2\times17$ 3 $3^2\times5\times17$ 4 $5^3\times17$

Question 2

HCF and LCM

Difficulty: easySource: NCERT Exercise 1.1 alignedTopic: fundamental-theorem-of-arithmetic

The HCF of $26$ and $91$ is $13$ . Their LCM is:

1 $91$ 2 $117$ 3 $182$ 4 $2366$

Question 3

Ending in zero

Difficulty: mediumSource: NCERT Exercise 1.1 alignedTopic: fundamental-theorem-of-arithmetic

Why can no power $6^n$ , $n$ a natural number, end in $0$ ?

1Its prime factorisation has no factor $2$ .2Its prime factorisation has no factor $3$ .3Its prime factorisation has no factor $5$ .4Every power of $6$ is prime.

Question 4

Theorem used in irrationality

Difficulty: easySource: NCERT Theorem 1.2 alignedTopic: irrational-numbers

If prime $p$ divides $a^2$ , the textbook theorem allows us to conclude:

1 $a$ divides $p$ 2 $p$ divides $a$ 3 $p=a^2$ 4 $a$ is prime

Question 5

Contradiction in the square-root proof

Difficulty: mediumSource: NCERT Exercise 1.2 alignedTopic: irrational-numbers

What contradiction completes the proof that $\sqrt5$ is irrational?

1Both numerator and denominator are divisible by $5$ although the fraction was in lowest form.2The denominator becomes zero.3The numerator is negative.4The square root becomes an integer.

Question 6

Rational plus irrational

Difficulty: mediumSource: NCERT Exercise 1.2 alignedTopic: irrational-numbers

Why is $6+\sqrt2$ irrational?

1Every sum is irrational.2If it were rational, subtracting $6$ would make $\sqrt2$ rational.3Six is irrational.4Its square is negative.

Question 7

Three-number HCF

Difficulty: easySource: NCERT Exercise 1.1 alignedTopic: ncert-exercises-and-revision

The HCF of $8$ , $9$ and $25$ is:

1 $1$ 2 $2$ 3 $5$ 4 $25$

Question 8

Circular path

Difficulty: mediumSource: NCERT Exercise 1.1 alignedTopic: ncert-exercises-and-revision

Two runners take $18$ minutes and $12$ minutes per lap. After how long will both again be at the start together?

1 $6$ minutes2 $24$ minutes3 $30$ minutes4 $36$ minutes

Loading...

Real Numbers quiz

Select your answers

Unique prime factorisation

HCF and LCM

Ending in zero

Theorem used in irrationality

Contradiction in the square-root proof

Rational plus irrational

Three-number HCF

Circular path

Preparing your questions...

Tell us what to fix next

Select your answers

Unique prime factorisation

HCF and LCM

Ending in zero

Theorem used in irrationality

Contradiction in the square-root proof

Rational plus irrational

Three-number HCF

Circular path