Question

multiple - choice. find the product.

1. 6.34×3.8

a. 11.148
b. 24.092
c. 24.414
d. 19.02

1. 2/3×2/5 = 4/15

a. 2/3
b. - 4/15
c. 4/15
d. 2/5

1. - 3 1/2×(- 3 1/10)

a. 1 4/31
b. 10 17/20
c. 9 1/20
d. 8 9/10

1. 2.43×12.4

a. 3.013
b. 14.81
c. 30.132
d. 33.148

1. 21×(- 12)

a. 252
b. 9
c. - 9
d. - 252
find the quotient.

1. 228.8÷22

a. 250.8
b. 10.4
c. 252.3
d. 11.9

1. 14.76÷4.1

a. 3.2
b. 3.8
c. 0.28
d. 3.6

1. 2/5÷5/6

a. 3
b. 12/25
c. 1/3
d. 2 1/12

Explanation:

Step1: Calculate 6.34×3.8

Multiply as whole - numbers: 634×38 = 24092. There are 2 + 1=3 decimal - places in the factors. So, 6.34×3.8 = 24.092.

Step2: Calculate $\frac{2}{3}\times\frac{2}{5}$

Multiply the numerators (2×2 = 4) and the denominators (3×5 = 15). So, $\frac{2}{3}\times\frac{2}{5}=\frac{4}{15}$.

Step3: Calculate $3\frac{1}{2}\times3\frac{1}{10}$

Convert mixed - numbers to improper fractions: $3\frac{1}{2}=\frac{7}{2}$ and $3\frac{1}{10}=\frac{31}{10}$. Then $\frac{7}{2}\times\frac{31}{10}=\frac{217}{20}=10\frac{17}{20}$.

Step4: Calculate 2.43×12.4

Multiply as whole - numbers: 243×124 = 30132. There are 2+1 = 3 decimal - places in the factors. So, 2.43×12.4 = 30.132.

Step5: Calculate 21×(-12)

The product of a positive and a negative number is negative. 21×12 = 252, so 21×(-12)= - 252.

Step6: Calculate 228.8÷22

228.8÷22 = $\frac{228.8}{22}=\frac{2288}{220}=10.4$.

Step7: Calculate 14.76÷4.1

14.76÷4.1=$\frac{14.76}{4.1}=\frac{147.6}{41}=3.6$.

Step8: Calculate $\frac{2}{5}\div\frac{5}{6}$

Dividing by a fraction is the same as multiplying by its reciprocal. So, $\frac{2}{5}\div\frac{5}{6}=\frac{2}{5}\times\frac{6}{5}=\frac{12}{25}$.

Answer:

1. B. 24.092
2. C. $\frac{4}{15}$
3. B. $10\frac{17}{20}$
4. C. 30.132
5. D. - 252
6. B. 10.4
7. D. 3.6
8. B. $\frac{12}{25}$