## Interview Question

Product Engineer Trainee Interview

-Mumbai

# In the 2nd round they asked: 1. An egg has to be boiled which takes exactly 11 minutes to boil. There are only 2 sand watches available to you one of 9 minutes and the other of 5 minutes. Using only these sand watches boil the egg.

1

It takes 4 flips to calculate 11 minutes. You have tu turn both sand watches same time as anyone of them is been finished first. \$ = 1 minute and @ = Flip. \$\$\$\$\$@\$\$\$\$@\$@\$ Explanation: Once 5 minute over and flip both watches. Timer is 4 minute and 5 minute as 4 minute over flip the watch so till now 9 minutes over now watches running for 1 minute and 9 minute. Once 1 minute over flip watches again watches running for 1 Minute and 5 Minute. Once one minute watch is finished egg is cooked.

Latesh Kolhe on

1

I ll start both watch After 5 mins I ll have 4 remaining in 9 min watch and 5 min watch will go down Then I ll start 5 min watch again When 9 min watch finishes it's time we will have 1 min remaining in 5 min watch Now I ll start 9 min watch again in 1 min I ll have 1 min sand down in 9 min watch and 5 min watch will have all its sand down Until now we are done with 10 mins with 5 min watch used 2 times Now we will use 1 min sand which is down in 9min watch to calculate 11 th min

0

start both hour glasses at 0 let 5 min hour glass be x and 9 min hour glass be y. after 5 min- x will have 0; y will have 4. turn and start;after 4 mins- x will have 1; y will have 0. Now start boiling the egg turn the glass and after 1 min x will have 0; y will 0; reset and start again. after 5 min- x will have 0; y will have 4. turn and start- after 4 min- x will have 1; y will have 0. turn and start after 1 min- total 1+5+4+1=11. done!

Sidarth on

2

It takes 4 flips to calculate 11 minutes. You have tu turn both sand watches same time as anyone of them is been finished first. \$ = 1 minute and @ = Flip. \$\$\$\$\$@\$\$\$\$@\$@\$ Explanation: Once 5 minute over and flip both watches. Timer is 4 minute and 5 minute as 4 minute over flip the watch so till now 9 minutes over now watches running for 1 minute and 9 minute. Once 1 minute over flip watches again watches running for 1 Minute and 5 Minute. Once one minute watch is finished egg is cooked.

Latesh Kolhe on

27

2. A shopkeeper sells 1 new bottle of cold drink in exchange of 5 empty bottles of cold drink. A guy had a party last Friday for which he bought 77 bottles of cold drink. After the party the guy has 77 empty bottles of cold drink. How many new bottles can the guy buy?

Anonymous on