The given table shows the number of formal learners, informal learners and illiterates, on the basis of gender, in the age group of 18-30 years in village X near Delhi. Determine the ratio among the formal learners, informal learners and illiterates.

FORMAL LEARNERS	BOYS	39
	GIRLS	52
INFORMAL LEARNERS	BOYS	65
	GIRLS	78
ILLITERATES	BOYS	143
	GIRLS	169

Correct option is D

Solution:
No of formal learners = 39 + 52 = 91
No of informal learners = 65 + 78 = 143
No of illiterates = 143 + 169 = 312
We can use the prime factorization method to find the GCD.
91 = 7 $$\times$$​13
143 = 11 $$\times$$​ 13
312 = 2 $$\times$$ 2 $$\times$$ 2 $$\times$$ 3$$\times$$13 
The common factor among these numbers is 13.
we divide each number by the GCD (13) to get the ratio
91 / 13 = 7
143 / 13 = 11
312 / 13 = 24
The required ratio;
= 7 : 11 : 24