Following chart shows experience (in years) for employees working in an organization. Employees with experience of 4 years and above are considered senior staff, while rest are considered junior staff. Find the number of senior staff in the organization.
Students from grade 8 class decided to collect money for earthquake relief. The amount (in SR) collected by each students equals to number of students in the class, If they collected a total of SR8836, how many students were there in the class?
A shopkeeper sells two qualities of coffee at the rates of SR44 per kg. and SR42 per kg, gaining 10% and 20% profit respectively. If he mixes the two variants in the ratio 2:3 and sells the mixture at SR40.7 per kg., what is his gain or loss?