Exercise

Edmond Halley an English Astronomer established that certain comet visible from earth in every $76$ years and predicted its visibilty from earth in $1758$ $\mathrm{AD}$. The comet is now known as Halley's comet. The first recorded sightings of what believed to be Halley's comet was in $240 \mathrm{BCE}$. 

Roughly, how many times did Halley's comet visible from earth during this period?

Shalini, Amber and Anant have dinner together. The bill for the dinner is $₹ 3277.50$. They divide it among themselves.

Shalini pays first, she rounds her share amount to the nearest tens. Amber pays next, he rounds his share amount to the nearest rupees. The remaining amount is paid by Anant.

What is the amount paid by Anant?

Shalini, Amber and Anant have dinner together. The bill for the dinner is $₹ 3277.50$. They divide it among themselves.

They have some starters, some drinks and the main course in the dinner. One-third of the bill was for drinks and one-fifth for starters.

What amount is paid for the main course?

Shalini, Amber and Anant have dinner together.

During the dinner, they have six glasses of drinks. Amber has one-half of them and Shalini has one-third of them. Anant has rest of them

How many glass/es does Anant have?

Insulin is a hormone made by the pancreas in the human body. It helps to regulate blood sugar level and absorbs glucose to get energy. The number of required units of insulin varies according to the individual. In some cases, an individual body is not able to produce sufficient amount of insulin. For those individuals, supplementary units of insulin are injected into the body.

A doctor uses this formula to calculate the daily insulin units required for Prakhar’s body. Daily insulin requirement (units) $= 0.55 \times$ Total body mass (kilograms)

Prakhar’s body mass is $80 kg$. What is Prakhar’s daily insulin requirement?

Insulin is a hormone made by the pancreas in the human body. It helps to regulate blood sugar level and absorbs glucose to get energy. The number of required units of insulin varies according to the individual. In some cases, an individual body is not able to produce sufficient amount of insulin. For those individuals, supplementary units of insulin are injected into the body.

Insulin also helps in disposing of carbohydrates in the human body. In Prakhar’s body, $14.5$ insulin units dispose of $290 grams$ of carbohydrate.

How many grams of carbohydrates are disposed of by $1$ insulin unit?

Carat $\left(K\right)$ is a unit to measure the purity of gold. The higher the carat, the purer the gold. $24K$ gold is considered as the purest gold with no traces of any other metal in it.

$22K$ gold has $2$ parts other metals present in it.

Countries have their own minimum acceptance standard for an item to be called a gold item.

The minimum accepted standard of gold is $10$carat in the US and $8$ carat in Denmark.

What is the difference in percentage of gold between the standards set by the two countries?

Round your answer to the nearest whole number.

The Bureau of Indian Standards (BIS), certiies the purity of gold jewellery using hallmark codes. The BIS hallmark codes for gold jewellery are given below.

Riya purchased a gold necklace weighing $20 g$ hallmarked $18K750$. How many grams of pure gold are in the necklace?