RK JHA Solutions for Chapter: Data Interpretation and Quantitative Ability, Exercise 7: Solved Paper 2014

Prof Suman takes a number of quizzes for a course. All the quizzes are out of $100$ . A student can get an A grade in the course if the average of her scores is more than or equal to $90$. Grade B is awarded to a student, if the average of her scores is between $87$and $89$(both included), if the average is below $87$, the student gets a C grade. Ramesh is preparing for the last quiz and he realises that he must score a minimum of $97$to get an A grade. After the quiz, he realises that be will score $70$ and he will just manage a B. How many quizzes did Prof Suman take?

A polynomial ${\mathrm{ax}}^3+{\mathrm{bx}}^2+\mathrm{cx}+\mathrm{d}$ intersects the $\mathrm{x}$-axis at $1$ and $-1$, $\mathrm{y}$-axis at $2$. The value of $\mathrm{b}$ is:

Triangle $ABC$ is a right angled triangle. $D$ and $E$ are mid points of $AB$ and $BC$ respectively. Read the following statements.

I. $AE=19$

II. $CD=22$,

III. Angle $B$ is a right angle.

Which of the following statements would be sufficient to determine the length of $AC$?

There are two windows on the well of a building that need repairs. A ladder $30 \mathrm{m}$ long is placed against a wall such that it just reaches the first window which is$26 \mathrm{m}$ high. The foot of the ladder is at point A. After the first window is fixed, the foot of the ladder is pushed backwards to point B, so that the ladder can reach the second window. The angle made by the ladder with the ground is reduced by half, as a result of pushing the ladder. The distance between points A and $B$ is

Aditya has a total of $18$ red and blue marbles in two bag (each bag has marbles of both colours). A marble is randomly drawn from the first bag followed by another randomly drawn from the second bag the probability of both being red is $\frac{5}{16}$ What is the probability of both marbles being blue?

A rectangular swimming pool is$48 \mathrm{m}$ long and $20 \mathrm{m}$ wide. The shallow edge of the pool is $1 \mathrm{m}$ deep. For every $2.6 \mathrm{m}$ that one walks up the inclined base of the swimming pool, one gains an elevation of $1 \mathrm{m}$. What is the volume of water (in cubic meters), in the swimming pool? Assume that the pool is filled up to be brim.

The probability that a randomly chosen positive divisor of ${10}^{29}$ is an integer multiple of ${10}^{23}$ is $\frac{{\mathrm{a}}^2}{{\mathrm{b}}^2}$, then ' b-a ' would be

A teacher noticed a strange distribution of marks in the exam. There were only three distinct scores $6,8$and $20$ The mode of the distribution was $8 .$ The sum of the scores of all the students was $504 .$ The number of students in the most populated category was equal to the sum of the number of students with lowest score and twice the number of students with the highest score. The total number of students in the class was