There are 29 girls and 20 boys in class one of the fifth grade. How many boys account for the whole class
五年级一班女生有29人，男生有20人，男生占全班人数的多少
<gadget id="calculator">29 + 20</gadget>
<output>49</output>

<gadget id="calculator">20 / 49</gadget>
<output>20/49 = around 0.408163</output>

<result>20/49 = around 0.408163</result>