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Hi;

The solution SP #346 is correct. Neat work, bobbym!

SP #347. If the sum of n terms of an A.P. is

, then which of its terms is 164?Hi;

The solution M #257 is correct. Marvelous, bobbym!

M #258. The slant height of the frustum of a cone is 4 cm, and the perimeter of its circular bases are 18 cm and 6 cm respectively. Find the curved surface area of the frustum.

Hi;

The solution #6141 (two values) is correct. Keep it up, bobbym!

#6142. Solve:

Hi;

The solution #3725 is correct (three parts). Excellent, bobbym!

#3726. Evaluate:

Hi;

The Answer #6510 is correct. Neat work, bobbym!

#6511. Name the city which was established in 1724 by a Spanish soldier, Bruno Mauricio de Zabala, as a strategic move amidst the Spanish-Portuguese dispute over the platine region. It was also under brief British rule in 1807. It hosted all the matches during the first FIFA World Cup. It has consistently been rated as having the highest quality of life of any city in Latin America: by 2015 it has held this rank every year during the last decade.

#6512. Name the Brazilian racing driver (21 March 1960 - 1 May 1994) who won three Formula One world championships for McLaren in 1988, 1990 and 1991 and is regarded as one of the greatest Formula One drivers of all time. He was killed in an accident while leading the 1994 San Marino Grand Prix for Williams. He has often been voted as the best and most influential Formula One driver of all time in various motorsport polls.

Hi;

The solution SP#345 is perfect. Excellent, bobbym!

SP #346. In a flower bed there are 23 rose plants in the first row, 21 in the second row, 19 in the third row and so on. There are five plants in the last row. How many rows are there in the flower bed?

Hi;

The solution M #256 (two parts) is correct. Splendid, bobbym!

M #257. A bucket is in the form of a frustum of a cone and holds 28.490 liters of water. The radii of the top and bottom are 28 cm and 21 cm respectively. Find the height of the bucket.

Hi;

The solution 631 is correct. Brilliant, bobbym!

632. In what ratio does the point C (3/5,11/5) divide the line segment joining the points A(3,5) and B(-3,-2)?

Hi;

The Answer #6508 is correct. Good work, bobbym!

#6509. What is 'Hyponatremia'?

#6510. It is an extra administration of a vaccine after an earlier (prime) dose. After initial immunization, it is a re-exposure to the immunizing antigen. It is intended to increase immunity against that antigen back to protective levels, after memory against that antigen has declined through time. What is it?

Hi;

The solution SP #344 is perfect. Excellent, bobbym!

SP #345. Along a road lie an odd number of stones placead at intervals of 10 meters. These stones have to be assembled around the middle stone. A person can carry only one stone at a time. A man carried the job with one of the end stones by carrying them in succession. In carrying all the stones he covered a distance of 3 km. Find the number of stones.

Hi;

The Answer #6506 is partially correct. Good work, bobbym!

#6507. Kunda Culture, with its roots in Swiderian culture, is a mesolithic hunter-gatherer communities of the Baltic forest zone extending eastwards through Latvia into northern Russia dating to the period 8000-5000 BC by calibrated radiocarbon dating. It is named after the this town of Kunda, about 110 kilometres (70 mi) east of Tallinn along the Gulf of Finland, near where the first extensively studied settlement was discovered on Lammasmäe Hill and in the surrounding peat bog. The oldest known Kunda culture settlement in this nation is Pulli settlement. The Kunda Culture is succeeded by the Narva culture who use pottery and show some traces of food production. In which nation is it?

#6508. It was created by Theodor Tobler (1876-1941) in Bern, Switzerland, in 1908. Theodor Tobler, with his cousin Emil Baumann, developed a unique milk chocolate including nougat, almonds and honey with a distinctive triangular shape. The image of a bear is hidden in the Matterhorn high mountain, symbolizing the town of the chocolate's origin. The triangular shape of the Matterhorn in the Swiss Alps is commonly believed to have given Theodor Tobler his inspiration for the shape of it. Name it.

Hi;

Both the Answers, #6503 and #6504, are correct. Excellent, bobbym!

#6505. Where or what is 'White Russia'?

#6506. What is 'Benelux'?

Hi;

The solution M #255 is correct. Brilliant, bobbym!

M #256. The radii of the circular ends of a frustum of height 6 cm are 14 cm and 6 cm respectively. Find the lateral surface area and total surface area of the frustum.

Hi;

The Answer #6502 is correct. Neat work, bobbym!

#6503. Who was 'Caligula' (meaning "little soldier's boot")?

#6504. Konrad Hermann Joseph Adenauer was a German statesman who served as the first post-war Chancellor of Germany (West Germany) from 1949 to 1963 (5 January 1876 – 19 April 1967). He led his country from the ruins of World War II to a productive and prosperous nation that forged close relations with France, the United Kingdom and the United States. Adenauer, the Chancellor till age 87 was dubbed "Der Alte". What does the name mean?

Hi;

The solution SP #343 is correct. Excellent, bobbym!

SP #344. 150 workers were engaged to finish a piece of work in a certain number of days. Four workers dropped the second day, four more workers dropped the third day and so on. It takes 8 more days to finish the work now. Find the number of days in which the work was completed.

Hi;

The Answer #6500 is correct. Neat work, bobbym!

#6501. Name the chemical element with atomic number 106. It is named after an American nuclear chemist. It is a synthetic element (an element that can be created in a laboratory but is not found in nature) and radioactive; the most stable known isotope has a half-life of approximately 3.1 minutes.

#6502. Name the hard, silvery grey, ductile, and malleable transition metal. The elemental metal is rarely found in nature, but once isolated artificially, the formation of an oxide layer (passivation) stabilizes the free metal somewhat against further oxidation. Andrés Manuel del Río discovered compounds of this metal in 1801 in Mexico by analyzing a new lead-bearing mineral he called "brown lead", and presumed its qualities were due to the presence of a new element, which he named *erythronium* (derived from Greek for "red") since, upon heating, most of the salts turned red.

Hi;

#6499. Which extremely radioactive synthetic element is named after the first ever Nobel Prize winner in Physics?

#6500. It exists as a highly toxic pale yellow diatomic gas at standard conditions. As the most electronegative element, it is extremely reactive: almost all other elements, including some noble gases, form compounds with this element. Name it.

Hi;

Both the Answers, #6495 and #6496, are correct. Magnificent, bobbym!

#6497. Many of the element's properties were predicted by Dmitri Mendeleev before the element was discovered. Mendeleev noted a gap in his periodic table and gave the undiscovered element the provisional name *ekamanganese (Em)*. In 1937, the element became the first predominantly artificial element to be produced, hence its name. Name it.

#6498. Name the superheavy synthetic element with symbol Mc and atomic number 115. It was first synthesized in 2003 by a joint team of Russian and American scientists at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia. In December 2015, it was recognized as one of four new elements by the Joint Working Party of international scientific bodies IUPAC and IUPAP. On 28 November 2016, it was officially named after the Moscow region, which the JINR is situated in.

Hi;

The solution 630 is correct. Marvelous, bobbym!

631. Point P divides the line segment joining the points A(2,1) and B(5,-8) such that AP/AB = 1/3. If P lies on the line 2x - y + k = 0, find the value of k.

Hi MathsIsFun,

This is a neat page. Thanks.

I feel Euler's chain rule may be included.

Hi;

The solution SP #342 is correct. Neat work, bobbym!

SP #343. The houses of a row are numbered consecutively from 1 to 49. Show that there is a value of x such that the sum of the numbers of the houses preceding the house numbered x is equal to the sum of the numbers of the houses following it. Find the value of x.

Hi;

The solution M #254 is correct. Keep it up, bobbym!

M #255. In the middle of a rectangular field measuring 30 m x 20 m, a well of diameter 7 m diameter and 10 m depth is dug. The earth so removed is evenly spread over the remaining part of the field. Find the height through which the level of the field is raised.

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#6495. The element usually occurs together with cerium and the other rare earth elements. It was first found by the Swedish chemist Carl Gustav Mosander in 1839 as an impurity in cerium nitrate - hence the name, from the Ancient Greek, meaning "to lie hidden". Although it is classified as a rare earth element, it is the 28th most abundant element in the Earth's crust, almost three times as abundant as lead. Name the element.

#6496. Name the element which was discovered using spectroscopy by French chemist Paul Emile Lecoq de Boisbaudran in 1875 from its characteristic spectrum (two violet lines) in a sample of sphalerite. Later that year, Lecoq obtained the free metal by electrolysis of the hydroxide in potassium hydroxide solution. He named the element after his native land of France.

Hi;

The Answer #6491 is correct. Neat work, bobbym!

#6493. Name the first commercially successful portable microcomputer, released on April 3, 1981. It weighed 10.7 kg (24.5 lb), cost $1,795 US, and ran the CP/M 2.2 operating system. Powered directly from a mains socket as it had no on-board battery, though it was still classed as a portable device as it could be packed away and transported by hand to another location.

#6494. Name the South Korean multinational conglomerate headquartered in Seoul. It was founded by Lee Byung-chul in 1938 as a trading company. Over the next three decades, the group diversified into areas including food processing, textiles, insurance, securities and retail. It entered the electronics industry in the late 1960s and the construction and shipbuilding industries in the mid-1970s; these areas would drive its subsequent growth. It has a powerful influence on South Korea's economic development, politics, media and culture and has been a major driving force behind the "Miracle on the Han River".

Hi;

The solution #6140 is correct. Neat work, bobbym!

#6141. Solve: