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.

Question

Bright Tutorials · Accepted Answer

(i) World population = 8.2 billion = 8.2 × 10
9
Pieces of clothing = 30 pieces per person
Total pieces of clothing = 8.2 × 10
9
× 30
= 246 × 10
9
= 2.46 × 10
11
pieces of clothing
(ii) No. of bee colonies = 100 million = 1 × 10
8
No. of bee per colony = 50,000 = 5 × 10
4
Total no. of bees = 1 × 10
8
× 5 × 10
4
= 5 × 10
8+4
= 5 × 10
12
honeybees
(iii) No. of bacterial cells per human body = 38 trillion = 3.8 × 10
13
World population (approx.) = 8.2 billion = 8.2 × 10
9
Total bacterial population = 3.8 × 10
13
× 8.2 × 10
9
= 31.16 × 10
13+9
= 31.16 × 10
22
(iv) Let average eating time per day = 1.5 hours
In seconds = 1.5 × 60 × 60 = 5400 = 5.4 × 10
3
and an average person’s lifetime (approx.) = 70 years
In seconds = 70 × 365 × 24 × 60 × 60
= 161,148,960,000
= 1.61 × 10
11
Total time spent in eating = 5.4 × 10
3
× 1.61 × 10
11
= 8.694 × 10
3+11
= 8.7 × 10
14
seconds

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