The students visited the planetarium, 160 people went to the fifth grade, more people went to the sixth grade than the fifth grade (1/4), and the number of the fourth grade went to the sixth grade (3/4). How many people went to the fourth grade?
同学们参观天文馆，五年级去了160人，六年级去的人数比五年级多(1/4)，四年级去的人数是六年级的(3/4)．四年级去了多少人？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 + (1/4)</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">160 * (5/4) * (3/4)</gadget>
<output>150</output>

<result>150</result>