Question

Years and Years
(a) Sohan drinks 8 glasses of water every day.
• How many glasses will he drink in one month? __________
• How many glasses will he drink in one year?
• If 125 people living in a colony drink 8 glasses of water in a day, how much water will they drink in a year?

(b) If Soha's heart beats 72 times in one minute, how many times does it beat in one hour?
• Now find out how many times it beats in one day.
• Count your own heart beats to find out how many times your heart beats in one week.

(c) A baby elephant drinks around 12 L of milk every day. How much milk will it drink in two years?

(d) A baby blue whale drinks around 200 L of milk in one day. Just imagine how much milk that is! Find out in how many days your family would use 200 L milk. How much milk would the baby blue whale drink in eight months?

Answer 1

(a)
• Number of glasses of water consumed by Sohan in 1 day = 8
We know
1 month = 30 days
∴ Number of glasses of water consumed by Sohan in 30 days = 30 × 8
= 240
Working:



Thus, Sohan will drink 240 glasses of water in one month.

• We know
1 year = 365 days
∴ Number of glasses of water consumed by Sohan in 365 days = 365 × 8
= 2,920
Working:



Thus, Sohan will drink 2,920 glasses of water in one year.

• Number of glasses of water consumed by 125 people of the colony in 1 day = 8
∴ Number of glasses of water consumed by 125 people of the colony in 365 days = 365 × 8
= 2,920
Working:



Thus, 125 people of the colony will drink 2,920 glasses of water in one year.

(b)
Number of times Soha's heart beats in 1 minute = 72
We know,
1 hour = 60 minutes
∴ Number of times Soha's heart beats in 60 minutes = 72 × 60
= 4,320
Working:



Thus, Soha's heart beats 4,320 times in one hour.

• We know
1 day = 24 hours
1 hour = 60 minutes
∴ 24 hours = 24 × 60 minutes
= 1,440 minutes
Number of times Soha's heart beats in 1 minute = 72
∴ Number of times Soha's heart beats in 1,440 minutes = 1440 × 72
= 1,03,680
Working:

Thus, Soha's heart beats 1,03,680 times in one day.

My heart beats 72 times in one minute.
We know
1 week = 7 days
1 day = 1,440 minutes
7 days = 7 × 1440 minutes
= 10,080 minutes
Working:

∴ Number of times my heart beats in 10,080 minutes = 10080 × 72
= 7,25,760
Working:

Thus, my heart beats 7,25,760 times in one week.

(c)
Amount of milk consumed by the baby elephant in 1 day = 12 L
We know
1 year = 365 days
2 years = 2 × 365 days
= 730 days
Working:



Now,
Amount of milk consumed by the baby elephant in 730 days = 730 × 12 L
= 8,760 L
Working:



Thus, the baby elephant will drink 8,760 L of milk in two years.

(d)
Amount of milk consumed by the baby blue whale in 1 day = 200 L
My family uses 5 L milk every day.
∴ Number of days in which 200 L of milk is consumed by my family = 200 ÷ 5
= 40

Working:



We know
1 month = 30 days
∴ Amount of milk consumed by the baby blue whale in 30 days = 200 × 30
= 6,000 L
Working:



Thus,
Amount of milk consumed by the baby blue whale in 1 month = 6,000 L
Amount of milk that will be consumed by the baby blue whale in 8 months = 6000 L × 8
= 48,000 L
Working:



Thus, the baby blue whale will drink 48,000 L of milk in eight months.