Let tn denote the nth triangular number. For what values of n does tn divide the sumti +

Fundamentals of Physics 10
The space between two concentric conducting spherical shells of radii b ! 1.70 cm and a ! 1.20 cm is filled with a substance of dielectric constant k 23.5. A potential difference V ! 73.0 V is applied across the inner and outer shells. Determine (a) the capacitance of the device, (b) the free charge

Chemistry 11
The formula of a hydrate of barium chloride is \(\mathrm{BaCl}_{2} \cdot x \mathrm{H}_{2} \mathrm{O}\). If 1.936 g of the compound gives 1.864 g of anhydrous \(\mathrm{BaSO}_{4}\) upon treatment with sulfuric acid, calculate the value of x.

Biology 8
Which process in the nephron is least selective? a. filtration d. secretion b. reabsorption e. salt pumping by the loop of Henle c. active transport

Introduction to Probability, 2
A motorist goes through 4 lights, each of which is found to be red with probability 1/2 . The waiting times at each light are modeled as independent normal random variables with mean 1 minute and standard deviation 1/2 minute. Let X be the total waiting time at the red lights. (a) Use the total proba

Elementary Statistics: A Step by Step Approach 8th ed. 8
Per Capita Income of Delaware Residents In a recent year, Delaware had the highest per capita annual income with $51,803. If s _ $4850, what is the probability that a random sample of 34 state residents had a mean income greater than $50,000? Less than $48,000? Source: New York Times Almanac. 0.9850;

Organic Chemistry 3
(a) Draw all stereoisomers of molecular formula C7H15Cl formed when (3S)-3-methylhexane is heated with Cl2. (b) Assuming that products having different physical properties can be separated by fractional distillation, how many different fractions would be obtained? (c) How many fractions would be opti

Biology: The Dynamics of Life 1
Interpret the interaction between a cowbird and a chipping sparrow as the sparrow raises the young of a brown-headed cowbird.

Plant Systematics 3
What is the difference between determinate and indeterminate inflorescence development?