A school has 960 pupils. If 3/5 are boys, how many girls are there? (2 marks) (b) A number is divisible by both 3 and 4. Give the smallest 3-digit number that meets this condition (2 marks) 23. Round off 78.456 to: (a) The nearest whole number (1 mark) (b) One decimal place (1 mark)

Nambari ndogo zaidi ya tarakimu 3 ni 100.
Gawanya 100 kwa 12:

$$\frac{100}{12} = 8 \text{ na baki ya } 4$$

Hii inamaanisha $12 \times 8 = 96$ (nambari ya tarakimu 2).
Nambari inayofuata ya tarakimu 3 ambayo ni zao la 12 ni:

$$12 \times 9 = 108$$

Nambari hii ni ya tarakimu 3 na inagawanyika na 3 na 4.

Jibu: $\boxed{\text{108}}$

Jumla ya sehemu ni 1.

$$\text{Sehemu ya wasichana} = 1 - \frac{3}{5} = \frac{5}{5} - \frac{3}{5} = \frac{2}{5}$$

$$\text{Idadi ya wasichana} = \frac{2}{5} \times 960$$ $$\text{Idadi ya wasichana} = 2 \times \frac{960}{5}$$ $$\text{Idadi ya wasichana} = 2 \times 192$$ $$\text{Idadi ya wasichana} = 384$$

Jibu: $\boxed{\text{384 wasichana}}$

Kwa kuwa 4 ni chini ya 5, tunazungusha chini (tunaacha nambari kamili kama ilivyo).

$$78.456 \approx 78$$

Jibu: $\boxed{\text{78}}$

Kwa kuwa 5 ni 5 au zaidi, tunazungusha juu tarakimu ya kwanza baada ya desimali.
Tarakimu ya kwanza baada ya desimali ni 4, kwa hivyo inakuwa 5.

$$78.456 \approx 78.5$$

Jibu: $\boxed{\text{78.5}}$