The product of two digits number is1998 if the product of thier units ...
Let the numbers be ab and xy, where a and x are the tenth place digits and b and y are the oneth place digits.
ab * xy = 1998
ax = 15
Only 5 and 3 are single digit numbers that yield the result 15
by = 28
Only 7 and 4 are single digit numbers that yield the result 28.
The units have to 7 and 4 and the tenth place digits are 5 and 3.
so the number is 57 * 34 or 37 *54
Of theise only 37 * 54 = 1998.
Therefore, the two numbers are 37 and 54.
This question is part of UPSC exam. View all Class 6 courses
The product of two digits number is1998 if the product of thier units ...
Problem:
The product of two digits number is 1998 if the product of their units digits is 28 and that of tens digits is 15. Find the numbers.
Solution:
To find the two-digit numbers, we need to consider their tens and units digits. Let's assume the tens digit of the first number is "a" and the units digit is "b". Similarly, the tens digit of the second number is "c" and the units digit is "d".
Step 1: Identify the given information:
- The product of the units digits is 28, so we have the equation b * d = 28.
- The product of the tens digits is 15, so we have the equation a * c = 15.
- The product of the two numbers is 1998, so we have the equation (10a + b)(10c + d) = 1998.
Step 2: Simplify the equations:
- From the equation b * d = 28, we can list the possible combinations of b and d that multiply to 28: (1, 28), (2, 14), (4, 7), (7, 4), (14, 2), (28, 1).
- From the equation a * c = 15, we can list the possible combinations of a and c that multiply to 15: (1, 15), (3, 5), (5, 3), (15, 1).
Step 3: Find the two-digit numbers:
- We need to find the combination of (a, c, b, d) that satisfies all the given equations.
- Let's try the different combinations of (a, c, b, d) and check if they satisfy the equation (10a + b)(10c + d) = 1998.
Possible combinations:
1. (1, 15, 1, 28): (10 * 1 + 1)(10 * 15 + 28) = 1999 * 178 = 355222 (Not equal to 1998)
2. (1, 15, 28, 1): (10 * 1 + 28)(10 * 15 + 1) = 281 * 151 = 42431 (Not equal to 1998)
3. (3, 5, 1, 28): (10 * 3 + 1)(10 * 5 + 28) = 31 * 78 = 2418 (Not equal to 1998)
4. (3, 5, 28, 1): (10 * 3 + 28)(10 * 5 + 1) = 58 * 51 = 2958 (Not equal to 1998)
5. (5, 3, 1, 28): (10 * 5 + 1)(10 * 3 + 28) = 51 * 58 = 2958 (Not equal to 1998)
6. (5, 3, 28, 1): (10 * 5 + 28)(10 * 3 + 1) = 78 * 31 = 2418 (Not equal to 1998)