40 candidates apply for a job 21 meet the height 17 meet the weight 18 meet both how many candidates but only the wait

Question

40 candidates apply for a job. 21 candidates meet the height. 70 candidates meet the weight. Eight candidates meet both weight and height. How many candidates me only the weight?

Answer 1

A Venn diagram is very useful.

 

For 40 candidates:

 

       21 meet the height                                 70 (not 17) meet the weight

          this is height only plus meet both      this is meet both plus weight only

                                             8 (not 18)meet both

So,        21-8 = 13 meet height only             70-8 = 62 meet weight only

 

If the numbers are 17 or 18, then plug them in to solve the problem.