Hari bought some files and pens in the ratio 7: 6. He spent a total of $198. A file cost $3 and a pen cost $2. (a) How many files did Hari buy? (b) If Hari bought one more file than pens, how many files and how many pens could he buy with the same amount of money? please help me!
Thanks million​

Ariana starts with 100 milligrams of a radioactive substance. the amount of the substance decreases by 20% each week for a number of weeks, w. the expression 100(1−0.2)w finds the amount of radioactive substance remaining after w weeks. which statement about this expression is true? a) it is the difference between the initial amount and the percent decrease. b) it is the difference between the initial amount and the decay factor after w weeks. c) it is the initial amount raised to the decay factor after w weeks. d) it is the product of the initial amount and the decay factor after w weeks.

What is the radius of the cone in the diagram? round your answer to the nearest whole number

Which equation could represent the relationship shown in the scatter plot? y=−3x−2 y=−3/4x+10 y=−2/3x+1 y=9x−12 scatter plot with x axis labeled variable x and y axis labeled variable y. points go from upper left to lower right.