To solve this, set up a system of equations.
Let a be the first digit and b the second.
Equation 1: a + b = 8
Equation 2: ab = 12
Solve for a variable: b = 12/a
Substitute that variable into the other equation: a + 12/a = 8
Solve for the 1st variable: a2 + 12 = 8a; a2 - 8a + 12 = 0, a = 6, 2
Solve for the 2nd variable: b = 12/a = 12/6 = 2
The number is 62.
(The 2 was crossed out for a because the number has to be between 30 and 90.)
12 and 2412 and 2412 and 2412 and 24
The least number of significant figures in any number of the problem determines the number of significant figures in the answer.
There are two numbers that satisfy the criteria. 38 and 83
It can have up to 5 digits.
When multiplying, the product is going to have the same number of significant digits as the least amount in the factors. So 8.08 has three significant digits and 5.232 has four significant digits. Remember that any zeros in-between significant digits is always significant. Because the least amount of sig digs in the factors is three (from 8.08), the product is going to have three sig digs.Multiplying out normally: 8.08 × 5.232 = 42.27456Rounded to three places: 42.3
52 is a number whose digits have a product of 10.
88
2 and 6
Try the different numbers - there are only 11 after all - and multiply their digits. Or analyze the factors of the number 21.
12 and 2412 and 2412 and 2412 and 24
The least number of significant figures in any number of the problem determines the number of significant figures in the answer.
19
There are two numbers that satisfy the criteria. 38 and 83
It can have up to 5 digits.
When multiplying, the product is going to have the same number of significant digits as the least amount in the factors. So 8.08 has three significant digits and 5.232 has four significant digits. Remember that any zeros in-between significant digits is always significant. Because the least amount of sig digs in the factors is three (from 8.08), the product is going to have three sig digs.Multiplying out normally: 8.08 × 5.232 = 42.27456Rounded to three places: 42.3
81
When using significant digits, the product has only the number of significant digits as the lowest number in the factors. "20" has two significant digits and "310" has three. Therefore, the product has to have two significant digits. 310 × 20 = 6200 6200 already has two significant digits.