Power Play (Exponents) | FIO

Question 6

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}

Check your answer with HomiSolve it yourself, then let Homi check your steps and spot mistakes.
Solution

We want to write the given number as a product of two or more powers in three different ways. We will use the rules of exponents.

Step 1 — Expressing 64364^3 in different ways

First, let us find the prime factorization of the base number, 64. 64=2×2×2×2×2×264 = 2 \times 2 \times 2 \times 2 \times 2 \times 2 =26= 2^6 So, we can write 64364^3 using the base 2. The rule (am)n=am×n(a^m)^n = a^{m \times n} means we multiply the exponents. 643=(26)364^3 = (2^6)^3 =26×3= 2^{6 \times 3}

218\boxed{2^{18}} We can also express 64 using other bases that are powers of 2. For example, 64=8264 = 8^2, because 8=238 = 2^3. 643=(82)364^3 = (8^2)^3 =82×3= 8^{2 \times 3} 86\boxed{8^6} Another way to express 64 is using base 4. We know 64=4364 = 4^3, because 4=224 = 2^2. 643=(43)364^3 = (4^3)^3 =43×3= 4^{3 \times 3} 49\boxed{4^9}

Step 2 — Expressing 1928192^8 in different ways

Let us find the prime factorization of the base number, 192. 192=2×96192 = 2 \times 96 =2×2×48= 2 \times 2 \times 48 =2×2×2×24= 2 \times 2 \times 2 \times 24 =2×2×2×2×12= 2 \times 2 \times 2 \times 2 \times 12 =2×2×2×2×2×6= 2 \times 2 \times 2 \times 2 \times 2 \times 6 =2×2×2×2×2×2×3= 2 \times 2 \times 2 \times 2 \times 2 \times 2 \times 3 =26×31= 2^6 \times 3^1 Now, we can apply the outer exponent, 8, to this product. The rule (a×b)n=an×bn(a \times b)^n = a^n \times b^n means we apply the exponent to each factor. 1928=(26×31)8192^8 = (2^6 \times 3^1)^8 =(26)8×(31)8= (2^6)^8 \times (3^1)^8 =26×8×31×8= 2^{6 \times 8} \times 3^{1 \times 8}

248×38\boxed{2^{48} \times 3^8} For a second way, we can express 192 as a product of a composite number and a prime number. We know 192=64×3192 = 64 \times 3. 1928=(64×3)8192^8 = (64 \times 3)^8 =648×38= 64^8 \times 3^8 648×38\boxed{64^8 \times 3^8} For a third way, we can split the prime factors of 192 differently. We know 192=26×3192 = 2^6 \times 3. We can write 262^6 as 23×232^3 \times 2^3. So, we can write 192192 as 23×23×32^3 \times 2^3 \times 3. 1928=(23×23×3)8192^8 = (2^3 \times 2^3 \times 3)^8 (23×23×3)8\boxed{(2^3 \times 2^3 \times 3)^8}

Step 3 — Expressing 32532^{-5} in different ways

First, let us find the prime factorization of the base number, 32. 32=2×2×2×2×232 = 2 \times 2 \times 2 \times 2 \times 2 =25= 2^5 Now, we can write 32532^{-5} using the base 2. The rule (am)n=am×n(a^m)^n = a^{m \times n} means we multiply the exponents. 325=(25)532^{-5} = (2^5)^{-5} =25×(5)= 2^{5 \times (-5)}

225\boxed{2^{-25}} For a second way, we can express the base 32 as a product of powers of 2. We know 32=2532 = 2^5. We can write 252^5 as 23×222^3 \times 2^2. So, we can write 3232 as 23×222^3 \times 2^2. 325=(23×22)532^{-5} = (2^3 \times 2^2)^{-5} (23×22)5\boxed{(2^3 \times 2^2)^{-5}} For a third way, we can express the base 32 as a product of powers using different bases. We need to find two powers whose product is 32. Let us try 43×214^3 \times 2^{-1}. We check this: 43×21=(22)3×21=22×3×21=26×214^3 \times 2^{-1} = (2^2)^3 \times 2^{-1} = 2^{2 \times 3} \times 2^{-1} = 2^6 \times 2^{-1}. The rule am×an=am+na^m \times a^n = a^{m+n} means we add the exponents when the bases are the same. 26×21=26+(1)2^6 \times 2^{-1} = 2^{6 + (-1)} =261= 2^{6-1} =25= 2^5 So, 43×214^3 \times 2^{-1} is indeed equal to 32. Now we can write 32532^{-5} using this expression for the base. 325=(43×21)532^{-5} = (4^3 \times 2^{-1})^{-5} (43×21)5\boxed{(4^3 \times 2^{-1})^{-5}}

Answer

(i) 64364^3 can be written as: 2182^{18} 868^6 494^9 (ii) 1928192^8 can be written as: 248×382^{48} \times 3^8 648×3864^8 \times 3^8 (23×23×3)8(2^3 \times 2^3 \times 3)^8 (iii) 32532^{-5} can be written as: 2252^{-25} (23×22)5(2^3 \times 2^2)^{-5} (43×21)5(4^3 \times 2^{-1})^{-5}

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?

← Back to Power Play (Exponents)