Home › RRB NTPC › Quantitative Aptitude › Number System › A number leaves remainder 3 when divided by 7 an…
A number leaves remainder 3 when divided by 7 and remainder 3 when divided by 5. The smallest such number above 3 is:
A33
B38
C35
D31
Answer & Solution
Correct answer: B. 38
1. If a number leaves the same remainder 3 with both divisors, then the number minus 3 is divisible by both.
2. So the number minus 3 must be a common multiple of 7 and 5.
3. Since 7 and 5 share no prime factor, their LCM is 7 x 5 = 35.
4. The smallest such value above 3 is therefore 35 + 3 = 38.
5. 33 and 31 are not 3 more than a multiple of 35, and 35 itself leaves remainder 0 with 5.
_Source: NCERT Class 10 Maths, Ch 1 'Real Numbers', S1.2 The Fundamental Theorem of Arithmetic_
Related questions
Before applying any solving method, an equation must first be written in its:Which two methods of solving quadratic equations are worked through in the examples?Because 2401 is the square of 49, that equation has roots that are:A number of toys problem leads to 2x squared plus x minus 300 equals 0. Its discriminant iThe roots of a quadratic equation are the same as the zeroes of the corresponding:The values of x that satisfy a quadratic equation are called its:A method that rewrites the equation so one side becomes a perfect square is called:The roots of x squared plus 4x minus 5 equals 0 are: