A payment of ₹120 is made with ₹10, ₹5, and ₹2 coins. A total of 25 coins are used. Which of the following is the number of ₹10 coins used in the payment?
5
Let the number of ₹10, ₹5, and ₹2 coins be X, Y and Z respectively.
Step 1: Write the equations from the problem:
Step 2:} Express Z in terms of X and Y:
\textbf{Step 3:} Substitute \(z\) into the value equation:
Step 4: Solve for integer values of X and Y:
Try X = 5:
Step 5: Find Z:
\[z = 25 - 5 - 10 = 10\]Since all values x = 5, Y=10, and z=10 are non-negative integers, the number of ₹10 coins used is 5.
Important Questions from Number System
A frog was at the bottom of an 80 m deep well. It attempted to come out of it by jumping. In each jump, it covered 1.15 m but slipped down by 0.75 m. The number of jumps after which it would be out of the well is:
The smallest perfect square number divisible by each of 6 and 12 is:
The L.C.M. of two different numbers are 30. Which of the following cannot be their H.C.F.?
Which is the least four-digit number which when divided by 5, 6 and 8 leaves remainder 2 in each case?
- A number when divided by 5 leaves a remainder 3.
What is the remainder when its square is divided by 5?
