Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

Hi;

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**anonimnystefy****Real Member**- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,037

Hi ganesh

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 23,196

Hi bobbym and anonimnystefy,

The solutions #4398, #4399, and #4400 are correct. Brilliant!

#4401. If log (0.57) =

, then what is the value of ?#4402. If log 2 = 0.30103, what is the number of digits of 2[sup]64[/sup]?

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

Hi;

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 23,196

Hi bobbym,

The solution #4401

The solution #4402 is correct. Good work!

#4403. If log 2 = 0.3010 and log 3 = 0.4771, find the values of

(a) log 25

(b) log 4.5

#4404. If log 2 = 0.30103, find the number of digits in 2[sup]56[/sup].

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

Hi;

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 23,196

Hi bobbym,

The solutions #4403 and #4404 are correct. Neat work!

#4405. A boat moves upstream at the rate of 1 kilometer in 12 minutes and downstream at the rate of 1 kilometer in 5 minutes. Find the speed of the current in kilometers per hour.

#4406. River is running at 3 kilometers per hour. It takes a man twice as long to row up as to down the river. Find the rate of the man in still water.

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

Hi;

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 23,196

Hi bobbym,

The solution #4406 is correct. Good work!

#4407. A man can row 6 kilometers per hour in still water. If the river is running at 1 kilometer per hour, it takes 90 minutes to row to a place and back. How far is the place?

#4408. A man rows at the rate of 10 kilometers per hour in still water and his rate against the current is 5 kilometers per hour, then what is the man's rate along the current?

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

Hi;

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 23,196

Hi bobbym,

The solutions #4407 and #4408 are correct. Excellent!

#4409. Two pipes can fill a tank in 4 hours and 8 hours respectively while third pipe empties the full tank in 10 hours. If all the three pipes operate simultatiously, in how much time the tank would be filled?

#4410. A electric pump can fill a tank in 5/2 hours. Because of a leak in the tank, it took 4 1/2 hours to fill the tank. In what time would the leak drain out all the water of the tank?

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

Hi ganesh;

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 23,196

Hi bobbym,

The solutions #4409 and #4410 are correct. Neat work!

#4411. A does half as much work as B in three-fourth of the time. If together they take 21 days to complete the work, how much time would B take to do it?

#4412. A can do a certain job in 15 days. B is 50% more efficient than A. Find the number of days it takes B to do the same piece of work.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

Hi;

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**anonimnystefy****Real Member**- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,037

Hi ganesh

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 23,196

Hi bobbym and anonimnystefy,

The solution #4411 is

Good work, bobbym!

The solution #4412 is correct, bobbym and anonimnystefy! Neat work!

#4413. A, B, and C together earn $350 per day. While A and C earn $200 and B and C together earn $180. Find the daily earning of C.

#4414. 4 men and 6 women finish a job in 8 days; while 3 men and 7 women finish it in 10 days. In how many days would 10 women working together finish it?

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

Hi ganesh;

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 23,196

Hi bobbym,

The solutions #4413 and #4414 are correct. Neat work!

#4415. Two persons A and B working together can dig a trench in 10 hours while A alone can dig it in 14 hours. In how many hours B alone can dig such a trench?

#4416. A and B can together finish a work in 40 days. They worked it for 30 days and then B left. The remaining work was done by A alone in 30 more days. In how many days A alone can finish the work?

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

Hi ganesh;

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 23,196

Hi bobbym,

The solutions #4415 and #4416 are correct. Good work!

#4417. Remo can complete a work in 12 days, working 8 hours a day. Mike can complete the same work in 8 days, working 10 hours a day. If Remo and Mike work together working 8 hours a day, in how many days can they complete the work?

#4418. 8 men and 12 boys take 12 days and 16 days to complete a job. 16 men began working on it but after 3 days, 10 men left and were replaced by 4 boys. In how many days the remaining work be completed by them?

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

Hi ganesh;

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 23,196

Hi bobbym,

The solutions #4417 and #4418 are correct. Good work!

#4419. If 18 workers can complete a job in 15 days, how many additional number of workers are required to complete the same job in 10 days?

#4420. A can do a piece of work in 5 days which B alone can do in 7 days. In how many days would they finish the work, both working together?

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**anonimnystefy****Real Member**- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,037

Hi ganesh

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

Hi;

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**ganesh****Administrator**- Registered: 2005-06-28
- Posts: 23,196

Hi anonimnystefy and bobbym,

The solutions #4419 and #4420 are correct. Excellent!

#4421. Express each number as a product of its prime factors:

(a) 140

(b) 156

(c) 3825

(d) 5005

(e) 7429

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline