the formula for compound interest is
where a is the amount after t years
p is the principal investment
r is the interest rate
n is the number of times it is compounded in a year
now plugging your given into this: p = 10,000, r = 2% or 0.02 in decimal form,
n = 4, since it is compounded quarterly, t = 5 years.
so maturity value = a = 10,000(1 + (0.02)/4)^(4x5) = php 11,048.96.
thus the interest = maturity value - principal = 11,048.96 - 10,000 = php 1,048.96.
hope this helps!