Multiplication of values from a list

I need the results it shows in the list to be multiplied by the corresponding value.
example:the entered value=10
10x1=10 result… acelerador3min= 10x3=30 acelerador5min= 10x5=50

values ​​are being saved in “Backendless”

the final value and the sum of the last added values

example: Acelererador1MIN=20 + Acelerador3MIN=30+Acelerador5MIN=40… Final anwser:1,5HOURS

I need to add, and then divide exemple (20+30+40)/60=1,5

there are two questions if you can help me i will be grateful

I didn’t find anything about sum of values ​​or multiplication or division so I thought I’d ask for help here, thanks for everything.

I use google translator, sorry for the mistakes in english

help me pls

did not work

I managed to find one of my answers

the value is multiplied