Calculation of true distance of a line measuring 160.42 m using a tape that is 0.02m too long

Problem
A 50-m steel tape that is is 0.02 m too long was used to measure the distance between two points A and B. If the measured distance was 160.42 m, calculate the correct distance between A and B.

A.   160.356 m C.   160.844 m
B.   160.484 m D.   160.563 m

 

Gas is escaping from a spherical balloon at a constant rate of 2 fˆ3/min. How fast is the outer surface area shrinking?

Problem
Gas is escaping from a spherical balloon at a constant rate of 2 ft3/min. How fast, in ft2/min, is the outer surface area of the balloon shrinking when the radius is 12 ft?

A.   1/2 C.   1/3
B.   1/5 D.   1/4

 

How many men paid for a total amount of $262,143.75 if the first person to arrive only paid 25 cents?

Problem
In a fund raising show, a group of philanthropists agreed that the first one to arrive would pay 25¢ to enter, and each later would pay twice as much as the preceding person. The total amount collected from all of them was \$262,143.75. How many of them paid?