OA : $180.29 SA : $60.06 MA : $68.65
I got a partly different answer: person is 35-45 years old, gross salary is around $1k.
Step 1 is to work backwards from the allocation rates. The current ones are here:
http://mycpf.cpf.gov.sg/NR/rdonlyre...01E9F4AE909/0/CPFAllocationRates1Sept2012.pdf
Total CPF contribution is $309. Take the MA contribution, it is 68.65/309 = 0.222. So the age is above 35 to 45 years old.
Step 2 is to consult the CPF Contribution Rate booklet for the age group. This is the above 35 to 50 year old one:
http://mycpf.cpf.gov.sg/NR/rdonlyre...79-2936365577D9/0/conbook_35to50_2011Sept.pdf
There are two brackets of total wages that give a CPF contribution of $309: $999.46-$999.99 (employee contribution $179) and $1000.00-$1001.64 (ditto $180). It is probably the round figure, $1k.
Some of you above used a 36% rate to calculate the gross salary. It does work most of the time, and for this age group, but NOT for this level of salary. 36% currently applies only to $1,500 and above. The effective CPF contribution rate of this earner is lower, at 30.9%.
From 1 Jan 2014, there will be some changes for low income-earners. In short, for this person earning $1k per month, the full 36% rate will apply. So the total CPF contribution will become $360, $200 from the employee and $160 from the employer (used to be $180 and $129). The employee will see a slight dip in take-home pay, but his overall salary grows.
Both links to the current allocation rates PDF and the contribution booklet PDF are from this page:
CPF Board - CPF Contribution Sep 2012 to Dec 2013 - my CPF 1. Info on the changes from 1 Jan 2014 is here:
CPF Board - CPF Contribution and Allocation Rates - my CPF 2
By the way, sorry to be intrusive, but if this person is eligible for Workfare, at monthly income of $1k, he/she can get $1,400 for a year, $560 in cash and $840 in CPF. Starting from next year, this becomes $2,100 a year.
CPF Board - Workfare Income Supplement (WIS) Scheme - my CPF 2