Unknown = x
the quotient of x and 12 is x/12 than 49 more than that is 53,
(x/12)+49=53, now use basic math and solve
-49 from both side,
x/12=4
*12 to both side,
x=48
therefore the unknown number is 48
Answer: C. 14
3 people weigh between 150-159
4 people wiegh between 160-169
7 people wiegh between 170-179