Question

What single discount will be equivalent to two successive discount of 8 percent and 5 percent

Answer 1

should be - 12.6 %
there is a shortcut trick
for increase (appreciation) take positive sign
for decrease (discount ) take negative sign
formula for 2 successive discounts or increase
$a + b + (ab \div 100)$
where a and b are successive discounts or increase values
for discounts take a and b values as -ive
for increase take a and b values as -ive
if the final value is negative means it's discount/decrease.
if the final value is +ive means it's a increase
here a will be -8% and b will be -5%
apply and get the answer.