Explanation

The main idea of the solar system was proposed by the Polish astronomer Nicolaus Copernicus (1473-1543).

who said that "the Sun is the centre of the Universe" and made the planets move around it in perfect circles

(in his book entitled, "On the Revolution of the Celestial Spheres", written in Latin and published in 1543)

Explanation

The image formed at the retina of the human eye is real and inverted.

 Real and inverted is due to the presence of a convex lens in the eye.

Explanation

Boycott Of Banu Hashim (617 AD – 619 AD)

Boycott was against the clan of Banu Hashim, declared in the 7th year of the Prophethood

Boycott was continued for 3 years

boycott declared by the leaders of Banu Makhzum and Banu Abd-Shams, two important clans of Quraysh.

the boycott was carried out to put pressure on Banu Hashim to withdraw its protection from Muhammad.

Additional Information

the Year of Sorrow is the Hijri year in which Muhammad's wife Khadijah and his uncle and protector Abu Talib died.

ND30-4-2023ND-21-5-2023

Explanation

Pakistan conducted a series of nuclear tests on 28 May 1998 at the Chagai test site, in Balochistan.

5 Nuclear tests were conducted by Pakistan at 15:15 hrs PST on 28 May 1998.

The tests were performed at Ras Koh Hills in the Chagai District of Balochistan Province.

Chagai-I was Pakistan's first public test of nuclear weapons.

while 

Chagai II

Chagai-II is the codename assigned to the second atomic test conducted by Pakistan, carried out on 30 May 1998

These tests followed the Chagai-I series

The test site was Kharan Desert, Pakistan

The number of tests is 1

Explanation

The mass ratio of carbon to hydrogen in methane is 3:1.

methane formula:CH4 C:H 1:4

It requires 3 grams of Carbon for one gram of Hydrogen. So, for 36 grams of Carbon, we require 12 grams of Hydrogen.

Explanation

The eighth amendment changed Pakistan's system of government from a parliamentary democracy to a semi-presidential system.

The eighth amendment strengthened the authority of the President and also granted additional powers to dismiss the elected Prime Minister's government.

Explanation

If we buying ourselves shop we must get our profit 

Explanation

Given, Loss =10 %=> CP 

CP−SP ×100=10

=> CPCP−180 ×100=10

=>CP−180=0.1CP

=>0.9CP=180

=>CP=200

To make a profit of 10 %, he must sell it at SP=CP+10 % of CP =200+20=Rs. 220

Explanation

x=0.5y=0.20.6−−−√×(3y)x =0.6−−−√×(3×0.2)0.5 =0.6−−−√×0.6−−−√=0.6

Explanation

Let the number be x
According to the question,
91 - 

 = x
9100 - 30x = 100x
Or, 9100 = 130x
Or, x = 

Hence, x = 70