Answer:
75 revolutions
8.25minutes
Step-by-step explanation:
If a long playing record revolves hundred times every three minutes, this can be written as;
100 revolution = 3minutes
To calculate the amount of revolution it will make in 2.25 minutes, we can write;
x = 2.25 minutes
Divide both expressions;
100/x = 3/2.25
3x = 100 * 2.25
3x = 225
x = 225/3
x = 75
Hence it can make 75 revolutions in 2.25 minutes
To determine how long it take for 275 revolutions, we can write;
275 revolutions = y
Recall that: 100 revolution = 3minutes
Divide;
275/100 = y/3
100y = 3 * 275
100y = 825
y = 825/100
y = 8.25
Hence it takes 8.25 minutes
