The mean of 12 observations is 15. One more observation is included and the new mean becomes 16. The 13th observation is

If two complimentary angles are in the ratio of 4:5, find the greater angle.

Mohan invested Rs. 100,000 in a garment business. After few months, Sohan joined him with Rs. 40000. At the end of the year, the total profit was divided between them in ratio 3:1. After how many months did Sohan join the business?

3 years ago, the ratio of Maya’s and Shikha’s age was 5:9 respectively. After 5 years, this ratio would become 3:5. Find present age of Maya?

Three numbers are in the ratio of 3:5:10 and their LCM is 630. Find their HCF.

Given that (a²+b²)=60, then find the value of (a+b)²+(a–b)².

In a factory, 60 workers can stitch 120 m of clothes in 7 days, what length of clothes can be stiched by 70 workers in 5 days?

Mukesh got series of discount 30%, 25%, 15% on his shirt. Find out the single equivalent discount.