Given :

• Gauri spends 0.75 of her salary every month.

• She earnes Rs. 12000 per/month.

To find :

• She SAVE Rs. 39000 in months = ?

Step-by-step explanation :

Gauri's total per month salary = Rs. 12000 [Given]

She spends every month = 0.75 part of her salary. [Given]

Question is saying that she saves 0.75 part of her salary in ONE month.

So, Every month she saves = One - she saves money in month.

Substituting the values, we get

= 1 – 0.75

= 0.25

Thus, Gauri saves every month = 0.25 part of her salary every month.

Gauri saves every month = she saves part of her salary every month × total salary of every month.

Substituting the values, we get,

= 0.25 × 12000

= 25/100 × 12000

= 25 × 120

= 3000

Thus, She saves in every month = Rs. 3000

But, Question is ASKING that in how many months Gauri save = Rs 39000.

She saves money in one month = Rs. 3000

Number of months she saves Rs 39000 = Her every month saving/She have to save money.

Substituting the values, we get,

= 39000/3000

= 13.

Thus, She saves Rs 39000 in 13 months.