The power supply bureau wants to replace 121 wooden utility poles with concrete utility poles (both ends included). Originally, every two wooden utility poles were 40 meters apart, but now every two concrete utility poles are 80 meters apart. How many cement utility poles are needed?
供电局要将121根木电线杆换成水泥电线杆(都含两端)，原来每两根木电线杆相距40米，现在每两根水泥电线杆相距80米，需要水泥电线杆多少根？
<gadget id="calculator">121 - 1</gadget>
<output>120</output>

<gadget id="calculator">120 * 40</gadget>
<output>4_800</output>

<gadget id="calculator">4_800 / 80</gadget>
<output>60</output>

<gadget id="calculator">60 + 1</gadget>
<output>61</output>

<result>61</result>