1.Spiral model is called a meta model.Spiral model is made
with the features of Prototype model and Waterfall model.
2.Spiral model takes special care about Risk Analysis.
Whreas it is not given importance in Prototype model.

Prototype model is suitable when the requirement of the
clent is not clear and it is supposed to be changed.
It doesn,t cover any risk management.
While Spiral model is an enhancement of the prototyping
model with so many extra features.Spiral model has the
facility of risk analysis and many more.

1.In spiral model risk is very high
while in prototype model risk is low.
2. Spiral model is used when requirement is not clear and needs conformation
while in prototype model requirement is clear but complex.
3. In spiral model customer interaction continous to move togather.
in other hand prototype model customer interaction needs till the prototype is approved.

You are given two candles of equal size which can burn 1
hours each. You have to measure 90 minutes with these
candles.( there is no scale or clock). Also u r given a
lighter.

John weight twice as much as Marciua. Marcia weight is 60%
of Bob's weight. Dave weight s 50% of lee weight 190% of
john weight. Which of these 5 person weight the least?

Find the 3 digits no. whose lat digit is the sqaure root of
the first root of the first digits and second digit is the
sum of the other two digits. And the number is divisble by
2,3,6,7. what is the number?