# Simultaneous random selection from three variables

**URL:** <https://discourse.psychopy.org/t/simultaneous-random-selection-from-three-variables/10981>\
**Category:** Builder\
**Created:** [February 13, 2020, 3:22pm UTC](https://discourse.psychopy.org/t/simultaneous-random-selection-from-three-variables/10981 "2020-02-13T15:22:50Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![M11](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.psychopy.org/m11/32/4334_2.png) [@M11](https://discourse.psychopy.org/u/M11)\
**Post date:** [February 13, 2020, 3:22pm UTC](https://discourse.psychopy.org/t/simultaneous-random-selection-from-three-variables/10981/1 "2020-02-13T15:22:51Z")

</div>

If this template helps then use it. If not then just delete and start from scratch.

**OS** (e.g. Win10):  
**PsychoPy version** (e.g. 3.2.4):  
\*\*Standard Standalone?: yes

Hello!

I would like to present simple arithmetics like 5 \* 3 = ,whereby the first number (digits between 1 and 99), signs (+, -, /, \*) and the second number should change randomly (e.g. trial 1: 15 – 7 = , trial 2 99/3 = , trial 3: 45 + 7 = etc).

With a simple Execel file with number1, number2, and sign as variable (and loop set random) only the rows are selected randomly, however I would like to present all three variables (number1, number2 and sign) randomly. How can I implement this?

Thank you very much!

M

---

<div class="post-metadata">

**Author:** ![Michael](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.psychopy.org/michael/32/16_2.png) [@Michael](https://discourse.psychopy.org/u/Michael)\
**Post date:** [February 13, 2020, 9:28pm UTC](https://discourse.psychopy.org/t/simultaneous-random-selection-from-three-variables/10981/2 "2020-02-13T21:28:32Z")

</div>

Is it as simple as having completely independent random selection of each term? i.e. most people could handle `99 / 3` but what about `99 / 7`? or `1 / 54`?

---

<div class="post-metadata">

**Author:** ![M11](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.psychopy.org/m11/32/4334_2.png) [@M11](https://discourse.psychopy.org/u/M11)\
**Post date:** [February 14, 2020, 8:00am UTC](https://discourse.psychopy.org/t/simultaneous-random-selection-from-three-variables/10981/3 "2020-02-14T08:00:53Z")

</div>

Dear Michael  
Thank you for the feedback. That´s a good point : ).  
I think, I should construct the task differently, e.g. digits between 1 and 9 (that should do for what I am planning).  
Do you have a solution how I can randomly select different numbers and signs within one routine and one excel file?

Thank you very much!