Element X is a radioactive isotope such that every 26
years,
its mass
decreases by half. Given that the initial mass of a sample of Element X is 680
grams, how much of the element would remain after 19 years, to the nearest
whole number?

What is the best approximation for the area of a circle with a radius of 4 m ? use 3.14 to approximate pi

Which equation is true? i. 56 ÷ 4·7 = 82 ÷ (11 + 5) ii. (24 ÷ 8 + 2)3 = (42 + 9)2 neither i nor ii ii only i and ii i only

Frank has a devised a formula for his catering business that calculates the number of meatballs he needs to prepare. the formula is m=4a+2c, where c=number of children; m=number of meatballs; a=number of adults. how many meatballs are required for a party of 10 adults and 5 children?