Surface area and Volumes
Cube
Lateral surface area: 4a**2
Total surface area: 6a**2
Volume: a**3
Cuboid
Lateral surface area: 2(l+b)h
Total surface area: 2(lb+bh+hl)
Volume: l*b*h
Cylinder
Curved Surface area: 2*pi*r*h
Total surface area: 2*pi*r(r+h)
Volume: pi*r**2*h
Cone:
Lateral surface area: pi*r*l
Total surface area: pi*r(r+l)
Volume: 1/3*pi*r**2*h
Sphere:
Surface area: 4*pi*r**2*h
Volume: 4/3*pi*r**2*h
1. Difference between simple interest & compound interest for 2 years = pr**2/100**2
2. Same for 3 years = pr**2(300+r)/100**3
3. Compound Interest > Simple Interest
4. Simple Interest = PTR/100
5. Amount = Principle + interest
6. Compound Interest = P(1+r/100)**n - p
Work and Time Apptitude Questions
Trick 1: If M1 men can finish W1 work in D1 days and M2 men can finish W2 work in D2 days then, the relation is: M1*D1/W1 = M2*D2/W2
Trick 2: If M1 men finish W1 work in D1 days, working T1 time each day and M2 men finish W2 work in D2 days, working T2 time each day, then the relation is: M1*D1*T1/W1 = M2*D2*T2/W2
Trick 3: If A completes a piece of work in ‘x’ days, and B completes the same work in ‘y’ days, then,
Work done by A in 1 day = 1/X
Work done by B in 1 day = 1/Y
Work done by A and B in 1 day = 1/X + 1/Y
Total time taken to complete the work by A and B both = XY/(X + Y)
Trick 4: If A can do a work in ‘x’ days, B can do the same work in ‘y’ days, C can do the same work in ‘z’ days, then the total time taken by A, B and C to complete the work together = XYZ/(XY + YZ + ZX)
Trick 5: If A alone can do a certain work in ‘x’ days and A and B together can do the same work in ‘y’ days, then B alone can do the same work in = XY/(X – Y)
Trick 7: If A can do a work in ‘x’ days and B can do the same work in ‘y’ days and when they started working together, B left the work ‘m’ days before completion then the total time taken to complete work is = (Y + M)X / (X+Y)
Trick 8: If A leaves the work ‘m’ days before its completion then the total time taken to complete work is = (X + M)Y / (X+Y)
Sorting Algorithms -
Selection Sort Questions : Inplace, Straight selection, Time Com, Space Com
Recuccernce relations for sorting algorithms.
Bubble Sort Questions: External sorting
GATE QUESTIONS
Sorting gate que
Bellmanford Algorithm
Huffman Coding
Variable length coding.
All pair shortest path problem
Floyed - Warshall Algorithm - Watch in UT
Travelling salesman Problem - web
Optimal merge Pattern.
Prim's Algorithm
krushkal Algorithm
Previous year GATE Questions
https://practicepaper.in/gate-cse/algorithm
https://www.geeksforgeeks.org/algorithms-gate-questions/
https://questions.examside.com/past-years/gate/gate-cse/algorithms
IP addresses and Fragmentation
https://cexpertvision.com/2021/03/19/numerical-practice-datagram-fragments/
Data link layer
1Q. A link has a transmission speed of 106 bits/sec. It uses data packets of size 1000 bytes each. Assume that the acknowledgement has negligible transmission delay, and that its propagation delay is the same as the data propagation delay. Also assume that the processing delays at the nodes are negligible. The efficiency of the stop-and-wait protocol in this setup is exactly 25%. The value of the one-way propagation delay (in milliseconds) is ___ Ans 12
2Q. Consider the sliding window algorithm where sender window size is 9 and receiver window size is 7 and no out of order arrivals. What is the smallest value for maximum sequence number?
3Q. Suppose two hosts are connected by a point-to-point link and they are configured to use stop and wait
5Q. A sender uses the stop and wait ARQ protocol for reliable transmission of frames. Frames are of size 100 bytes and the transmission rate at the sender is 20 Kbps. Size of an acknowledgement is 10 bytes and the transmission rate at the receiver is 8 Kbps. The one way propagation delay is 10 msec.
Assuming no frame is lost, the sender throughput is ________ bytes/sec.
6Q. In the GO back N ARQ sender is sending the 20 packets to the destination with a window size of 4. Every sixth packet is lost and after a packet loss sender is sending one dummy packet outside the window for ensuring everything is correct [ dummy packet is an outside packet not the part of the window]. How many number of transmissions will be there?
Transport layer questions:
1Q. Assume a TCP implementation over a 10Gbps link with one way dealy of 80ms if TCP receiver window size is 2MB and TCP send 1KB packet then how many RTT does it take until slow start phase open the congesion windows of 2MB. Assume no congestion and no loss of packet.3Q. Which layer connects the network support layers and user support layers ? solution
5Q. Suppose Host A sends two TCP segments back to back to Host B over a TCP connection. The first segment has sequence number 90; the second has sequence number 110.
def reverseWords(s: str) -> str: words = s.split() return ' '.join(word[::-1] for word in words)