Question

how many students took the survey?

Explanation:

Step1: Sum all the numbers in the Venn diagram and the rectangle

$$7 + 2+13 + 4+3 + 8+10+6$$

Step2: Calculate the sum

$$7+2 = 9$$
$$9+13 = 22$$
$$22+4 = 26$$
$$26+3 = 29$$
$$29+8 = 37$$
$$37+10 = 47$$
$$47+6 = 53$$

Answer:

53