a seasonal prevailing wind in the region of South and Southeast Asia, blowing from the southwest between May and September and bringing rain (the wet monsoon ), or from the northeast between October and April (the dry monsoon ).
a monsoon is traditionally a seasonal reversing wind accompanied by corresponding changes in precipitation, the summer monsoon is associated with heavy rainfall. it usually happens between April and September. as winter ends, warm, moist air from the southwest Indian Ocean blows toward countries like India, Sri Lanka, Bangladesh, and Myanmar. the summer monsoon brings a humid climate and torrential rainfall to these areas. India, Costa Rica, and Nicaragua are main locations. while too little rainfall during the summer monsoon can cause dire conditions for farmers on land, too much rainfall and overly strong winds can make coastal waters unsafe, preventing fishermen throughout South Asia from heading to sea to catch the fish they depend on for income. in dry climates, monsoons are an important replenishment for life as water is brought back into drought-stricken zones of the world. But the monsoon cycle is a delicate balance. If rains start late, are too heavy, or not heavy enough, they can spell disaster for people's livestock, crops, and lives.
So Adenine and Thymine are base pairs so they have to be equal to each other. So Adenine and Thymine are both 15% or 30% together.
This means there is still 70% left.
The next base pair is Cytosine and Guanine. they also have to equal to each other. Since there is 70% left you divide that number by two and you get 35%.