Correct

两下子

/ liǎngxiàzi / 
Strokes

Definition

a couple of times/to repeat the same/the same old trick/tricks of the trade

Example

As a Measure word

a couple of times; a few times; several times

1
Zhè
这
jī
几
dào
道
tí
题
jiǎndān
简单
  
,
tā
他
liǎngxiàzi
两下子
jiù
就
zuò
做
wán
完
le
了
  
。

These questions are rather simple. He finished them without much effort.

2
Wǒ
我
liǎngxiàzi
两下子
jiù
就
bǎ
把
dīngzi
钉子
zá
砸
jìnqù
进去
le
了
  
。

I drove in the nail with a few strokes of the hammer.

3
Tā
他
zhēngzhá
挣扎
le
了
liǎngxiàzi
两下子
xiǎng
想
zhàn
站
qǐlai
起来
  
,
dàn
但
méi
没
chénggōng
成功
  
。

He struggled several times to get on his feet, but failed.

As a Noun

a few tricks/skills of a trade

4
Tā
他
jiù
就
huì
会
zhè
这
liǎngxiàzi
两下子
  
,
biède
别的
shénme
什么
běnshì
本事
yě
也
méiyǒu
没有
  
。

He knows only these tricks. Nothing more.

5
Nǐ
你
zhēn
真
yǒu
有
liǎngxiàzi
两下子
  
!

You really are smart! / You're cool!