Topics

General Knowledge
General Science
General English
Aptitude
General Computer Science
General Intellingence and Reasoning
Current Affairs
Exams
Elementary Mathematics
English Literature

In a rare coin collection, there is one gold coin for every three non-gold coins. 10 more gold coins are added to the collection and the ratio of gold coins to non-gold coins would be 1 : 2. Based on the information; the total number of coins in the collection now becomes.

A) 90
B) 80
C) 60
D) 50

Correct Answer:

A) 90

Description for Correct answer:
Let the number of gold coins initially be x

and the number of non-gold coins be y.

According to the question,

3x = y

When 10 more gold coins, total number gold coins become x + 10

and the number non-gold coins remain the same at y.

Now, we have \( \Large 2 \left(10+x\right)=y \)

Solving these two equations, we get

x = 20 and y = 60.

Total number of coins in the collection at the end is equal to

x+10+y = 20+10+60 = 90.

Part of solved Linear Equations questions and answers : >> Aptitude >> Linear Equations

Comments

Similar Questions

1). If \( \Large \frac{\sqrt{3+x}+\sqrt{3-x}}{\sqrt{3+x}-\sqrt{3-x}}=2 \), then x is equal to

A). \( \Large \frac{5}{12} \)

B). \( \Large \frac{12}{5} \)

C). \( \Large \frac{5}{7} \)

D). \( \Large \frac{7}{5} \)

2). In an examination, a student scores 4 marks for every correct answer and losses 1 mark for every wrong answer. A student attempted all the 200 questions stud and scored 200 marks. Find the number of questions he answered correctly.

A). 82

B). 80

C). 68

D). 60

3). The graphs of ax + by = c, dx + ey = f will be
I. parallel, if the system has no solution.
II. coincident, if the system has finite numbers of solutions.
III. intersecting, if the system has only one solution.
Which of the above statements are correct?

A). Only I and II

B). Only ll and Ill

C). Only I and III

D). I, II and Ill

4). If \( \Large 3^{x+y}=81 \) and \( \Large 81^{x-y}=3 \), then what is the value of x?

A). \( \Large \frac{17}{16} \)

B). \( \Large \frac{17}{8} \)

C). \( \Large \frac{17}{4} \)

D). \( \Large \frac{15}{4} \)

5). Ten chairs and six tables together cost Rs.6200, three chairs and two tables together cost Rs.1900. The cost of 4 chairs and 5 tables is

A). Rs.3000

B). Rs.3300

C). Rs.3500

D). Rs.3800

6). The system of equations 3x + y - 4 = 0 and 6x + 2y - 8 = 0 has

A). a unique solution x = 1, y=1

B). a unique solution x = 0, y = 4

C). no solution

D). infinite solutions

7). If x+ y - 7 = 0 and 3x + y -13 = 0, then what is \( \Large 4x^{2} + y^{2} + 4xy\) equal to?

A). 75

B). 85

C). 91

D). 100

8). The solution of the equations \( \Large \frac{p}{x}+\frac{q}{y} \ and \ \frac{q}{x}+\frac{p}{y} \) n is

A). \( \Large x=\frac{q^{2}-p^{2}}{mp-nq}, y=\frac{p^{2}-q^{2}}{np-mq} \)

B). \( \Large x=\frac{p^{2}-q^{2}}{mp-nq}, y=\frac{q^{2}-p^{2}}{np-mq} \)

C). \( \Large x=\frac{p^{2}-q^{2}}{mp-nq}, y=\frac{p^{2}-q^{2}}{np-mq} \)

D). \( \Large x=\frac{q^{2}-p^{2}}{mp-nq}, y=\frac{q^{2}-p^{2}}{np-mq} \)

9). If \( \Large \frac{3}{x+y}+\frac{2}{x-y}=2 \) and \( \Large \frac{9}{x+y}-\frac{4}{x-y}=1 \), then what is the value of \( \Large \frac{x}{y} \)?

A). \( \Large \frac{3}{2} \)

B). 5

C). \( \Large \frac{2}{3} \)

D). \( \Large \frac{1}{5} \)

10). If \( \Large \frac{a}{b}-\frac{b}{a}=\frac{x}{y} \) and \( \Large \frac{a}{b}+\frac{b}{a}= x - y \) , then what is the value of x?

A). \( \Large \frac{a+b}{a} \)

B). \( \Large \frac{a+b}{b} \)

C). \( \Large \frac{a-b}{a} \)

D). None of these