Power Play (Exponents) | FIO

Question 1

Express the following in exponential form:

(i) 6×6×6×66 \times 6 \times 6 \times 6

(ii) y×yy \times y

(iii) b×b×b×bb \times b \times b \times b

(iv) 5×5×7×7×75 \times 5 \times 7 \times 7 \times 7

(v) 2×2×a×a2 \times 2 \times a \times a

(vi) a×a×a×c×c×c×c×da \times a \times a \times c \times c \times c \times c \times d

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Solution

We use exponential form to write repeated multiplication in a shorter way.

Step 1 — Understanding Exponents

When a number or variable multiplies itself, we use exponents. The base is the number being multiplied. The exponent shows how many times the base is used. For example, x×x×xx \times x \times x means xx is multiplied by itself 33 times. We write this as x3x^3. Here, xx is the base and 33 is the exponent.

(i) Express 6×6×6×66 \times 6 \times 6 \times 6 in exponential form.

The base is 66. It is multiplied 44 times.

6×6×6×66 \times 6 \times 6 \times 6

64\boxed{6^4}

(ii) Express y×yy \times y in exponential form.

The base is yy. It is multiplied 22 times.

y×yy \times y

y2\boxed{y^2}

(iii) Express b×b×b×bb \times b \times b \times b in exponential form.

The base is bb. It is multiplied 44 times.

b×b×b×bb \times b \times b \times b

b4\boxed{b^4}

Step 2 — Combining Different Bases

Sometimes, different numbers or variables are multiplied together. We write each one in its own exponential form. Then we multiply these exponential forms.

(iv) Express 5×5×7×7×75 \times 5 \times 7 \times 7 \times 7 in exponential form.

For the number 55, the base is 55. It is multiplied 22 times. For the number 77, the base is 77. It is multiplied 33 times.

5×5×7×7×75 \times 5 \times 7 \times 7 \times 7 =(5×5)×(7×7×7)= (5 \times 5) \times (7 \times 7 \times 7)

52×73\boxed{5^2 \times 7^3}

(v) Express 2×2×a×a2 \times 2 \times a \times a in exponential form.

For the number 22, the base is 22. It is multiplied 22 times. For the variable aa, the base is aa. It is multiplied 22 times.

2×2×a×a2 \times 2 \times a \times a =(2×2)×(a×a)= (2 \times 2) \times (a \times a)

22×a2\boxed{2^2 \times a^2}

(vi) Express a×a×a×c×c×c×c×da \times a \times a \times c \times c \times c \times c \times d in exponential form.

For variable aa, the base is aa. It is multiplied 33 times. For variable cc, the base is cc. It is multiplied 44 times. For variable dd, the base is dd. It is multiplied 11 time.

a×a×a×c×c×c×c×da \times a \times a \times c \times c \times c \times c \times d =(a×a×a)×(c×c×c×c)×d= (a \times a \times a) \times (c \times c \times c \times c) \times d

a3×c4×d\boxed{a^3 \times c^4 \times d}

Answer

(i) 646^4 (ii) y2y^2 (iii) b4b^4 (iv) 52×735^2 \times 7^3 (v) 22×a22^2 \times a^2 (vi) a3×c4×da^3 \times c^4 \times d

More questions in FIO

Q1

Express the following in exponential form:

(i) 6×6×6×66 \times 6 \times 6 \times 6

(ii) y×yy \times y

(iii) b×b×b×bb \times b \times b \times b

(iv) 5×5×7×7×75 \times 5 \times 7 \times 7 \times 7

(v) 2×2×a×a2 \times 2 \times a \times a

(vi) a×a×a×c×c×c×c×da \times a \times a \times c \times c \times c \times c \times d

Q2

Express each of the following as a product of powers of their prime factors in exponential form:

(i) 648

(ii) 405

(iii) 540

(iv) 3600

Q3

Write the numerical value of each of the following:

(i) 2×1032 \times 10^3

(ii) 72×237^2 \times 2^3

(iii) 3×443 \times 4^4

(iv) (3)2×(5)2(-3)^2 \times (-5)^2

(v) 32×1043^2 \times 10^4

(vi) (2)5×(10)6(-2)^5 \times (-10)^6

Q4

Find out the units digit in the value of 2224÷4322^{224} \div 4^{32}? [Hint: 4=224 = 2^2]

Q5

There are 5 bottles in a container. Every day, a new container is brought in. How many bottles would there be after 40 days?

Q6

Write the given number as the product of two or more powers in three different ways. The powers can be any integers.

(i) 64364^3 (ii) 1928192^8 (iii) 32532^{-5}

Q7

Examine each statement below and find out if it is 'Always True', 'Only Sometimes True', or 'Never True'. Explain your reasoning.

(i) Cube numbers are also square numbers.

(ii) Fourth powers are also square numbers.

(iii) The fifth power of a number is divisible by the cube of that number.

(iv) The product of two cube numbers is a cube number.

(v) q46q^{46} is both a 4th power and a 6th power (qq is a prime number).

Q8

Simplify and write these in the exponential form.

(i) 102×10510^{-2} \times 10^{-5}

(ii) 57÷545^7 \div 5^4

(iii) 97÷949^{-7} \div 9^4

(iv) (132)3(13^{-2})^{-3}

(v) m5n12(mn)9m^5n^{12}(mn)^9

Q9

If 122=14412^2 = 144 what is

(i) (1.2)2(1.2)^2

(ii) (0.12)2(0.12)^2

(iii) (0.012)2(0.012)^2

(iv) 1202120^2

Q10

Circle the numbers that are the same—

24×362^4 \times 3^6            64×326^4 \times 3^2            6106^{10}            182×6218^2 \times 6^2            6246^{24}

Q11

Identify the greater number in each of the following—

(i) 434^3 or 343^4

(ii) 282^8 or 828^2

(iii) 1002100^2 or 21002^{100}

Q12

A dairy plans to produce 8.5 billion packets of milk in a year. They want a unique ID (identifier) code for each packet. If they choose to use the digits 0–9, how many digits should the code consist of?

Q13

64 is a square number (828^2) and a cube number (434^3). Are there other numbers that are both squares and cubes? Is there a way to describe such numbers in general?

Q14

A digital locker has an alphanumeric (it can have both digits and letters) passcode of length 5. Some example codes are G89P0, 38098, BRJKW, and 003AZ. How many such codes are possible?

Q15

The worldwide population of sheep (2024) is about 10910^9, and that of goats is also about the same. What is the total population of sheep and goats?

(ii) 20920^9

(ii) 101110^{11}

(iii) 101010^{10}

(iv) 101810^{18}

(v) 2×1092 \times 10^9

(vi) 109+10910^9 + 10^9

Q16

Calculate and write the answer in scientific notation:

(i) If each person in the world had 30 pieces of clothing, find the total number of pieces of clothing.

(ii) There are about 100 million bee colonies in the world. Find the number of honeybees if each colony has about 50,000 bees.

(iii) The human body has about 38 trillion bacterial cells. Find the bacterial population residing in all humans in the world.

(iv) Total time spent eating in a lifetime in seconds.

Q17

What was the date 1 arab/1 billion seconds ago?

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