Sam was doing his Khan Academy assignments. The ratio of the number of problems Sam got incorrect to the number of problems he got correct is 2 : 7.
If Sam got 6 problems incorrect, how many problems did he get correct?
If Sam got 56 problems correct, how many problems did he get incorrect?

Equation for the calculation double 2 and then add 5

An airplane travels at an unknown elevation before it descends 3 miles to an elevation of 15 miles. find the elevation of the plane before its descen.

If the car had not hit the fence, how much farther would it have skidded? solve the skid-distance formula to find the extra distance that the car would have traveled if it had not hit the fence. round your answer to two decimal places. note that unit conversion is built into the skid distance formula, so no unit conversions are needed.