When $(10^5 \cdot 10^{77} \div 10^{15} )\div \left(10^{15}\right)^4$ is written as a single integer with no exponents, it is a 1 followed by one or more zeroes. How many zeroes are there?
I get $(10^5 \cdot 10^{77} \div 10^{15} )\div \left(10^{15}\right)^4 = (10^{82} \div 10^{15}) \div \left(10^{15}\right)^4$. I get $(10^{82} \div 10^{15}) \div \left(10^{15}\right)^4 = 10^{67} \div \left(10^{15}\right)^4$. I get $10^{67} \div \left(10^{15}\right)^4 = 10^{67} \div 10^{60}$. I get $10^{67} \div 10^{60} = 10^{67 - 60} = 10^7$. This means that the expression is equal to 10,000,000, which is a 1 followed by 7 zeroes. 